Step 4 - Temporarily mount the small bulb in a
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When excessive amperage has been drawn through a relay circuit it can cause
second half of the relay is the "switch" that controls power to a particular accessory
monitoring or connecting a separate circuit that uses power when the relay is
electromagnet to close (connect) the secondary electrical circuit inside the
"switch" that connects electrical current from one terminal to the other. Step 14 - When replacing a relay be sure to match
Once
In short, when the primary side of the relay (electromagnet) is activated, it
When testing relay circuits for power, ground is accidentally contacted
long enough so the bulb can be seen while driving.)
Bad contact points can cause a voltage drop. The bulb will now illuminate
Additional Testing
This condition will run down the battery until
reinstall the relay (PDC) cover. high amperage electrical circuit with a low amperage one, for example a radiator
In this article, we will show what resistance readings you should get when you measure various points of a relay. controls it, a relay is used to bridge this circuit to prevent electrical damage.
Use the test light grounded to check for power, and then switch the test
if these tests check out, the accessory is bad and needs to be replaced. Once
By far, the easiest way to test a suspect fuel pump relay — or some other automotive relay — is to swap the suspect relay … SPONSORED LINKS
second half of the relay is the "switch" that controls power to a particular accessory
The bulb will now illuminate
the relay contacts to "stick" not allowing the power to be shut off to the accessory.
A side marker bulb and socket work great because of its small size, make the wires
of time (hot) or when the amperage of the accessory has increased beyond its designed
causing the fuse to fail.
reinstall the relay (PDC) cover.
when the relay is use, and will go out to signal a failure. to check for power at the wiring harness (either wire). reinstall the relay (PDC) cover. If there is no power, the
Intermitted Failure
grasp or touch the relay in question, have a helper turn the ignition key to the
the relay can short circuit causing the electrical flow to stop, when the relay
dealing with a relay problem, is the problem with the relay itself or is the problem
Step 5 - This test can be used to test all aspects
Once
There are two tests that should be considered when
87a can be used for many different things such as relay activation
Moister can get inside a relay hindering the relay operation. Step 5 - This test can be used to test all aspects
The headlight relay is relatively easy to test, provided that you know what to look for and take the proper safety precautions. the orientation is correct or the relay will not work. If no power is observed at
( Note: if the circuit is computer controlled a delay could be programmed
Testing Fuses
circuit.) (adsbygoogle = window.adsbygoogle || []).push({});
switch the current ON or OFF in the second circuit.
Step 13 - Next, use a piece of wire automotive
to all relay controlled circuits. dealing with a relay problem, is the problem with the relay itself or is the problem
These
A relay is switch that utilizes an electrical trigger signal to activate.
base.
Small automotive bulb and socket
Step 6 - Once the relay has been removed, inspect
accessories can range from the main computer PCM (powertrian control module), radiator
service manual. light lead to the power side of the battery to check for circuit ground.
Step 13 - Next, use a piece of wire automotive
Step 16 - Once proper relay operation has resumed,
which are common, remove the relay in question, take a small wire strand, about
an electromagnet to close the secondary electrical circuit. reinstall the relay (PDC) cover. like a fuel pump or ignition system. When excessive amperage has been drawn through a relay circuit it can cause
When a relay warm up as in normal operation, the electrical contacts inside
accessories can range from the main computer PCM (powertrian control module), radiator
A rely should be considered as two separate halves, the primary side which utilizes
Testing Circuit 87 and 30
These
This electromagnet is activated by a simple power (+) and ground (-)
Use the ground test light to check if there is power, and then switch the test light to the battery power part to check if there is ground circuit. on position, then crank the engine over, the relay should click in one of the ignition
visible area to be seen while driving, masking taped to the hood or dash works well. activated by a simple power (+) and ground (-) much like a light bulb circuit.
each end to terminals 86 and 85. accessory should activate, if so the relay has failed. The bulb will now illuminate
the wire strand inserted and clear of any other terminals or metal (ground).
the relay terminals for signs of extreme heat or corrosion. relay to operate. illustrated in the picture below while testing the tail light socket. not working there is a good chance the contacts inside the relay have shorted. New Relay Installed
Testing Circuit 86 and 85
A relay is prone to failure when used for a long periods
two inches long and insert it into the relay connector terminal 87 or 30. into the operation of the accessory, additionally if a cooling fan is being tested
activated the relay connects an electrical supply to a particular accessory. up the terminal location from the old relay to to the new unit. the orientation is correct or the relay will not work. Example: Testing the
A relay is prone to failure when used for a long periods
Step 10 - Each terminal is identified at the relay
if not continue to next step.
Inspecting Relay Terminals
fan, fuel pump, door locks etc. SPONSORED LINKS
Step 15 - When installing the new relay be sure
Reinstall Relay Cover
closes the contacts (switch) to supply power to operate the accessory. (adsbygoogle = window.adsbygoogle || []).push({});
shorted. Step 3 - With the wire strand secured in the relay
electrical system must be tested starting with the fuse then the relay. when the relay is use, and will go out to signal a failure. Reinstall Relay Cover
long enough so the bulb can be seen while driving.) two inches long and insert it into the relay connector terminal 87 or 30. Intermitted Failure
In short, when the primary side of the relay (electromagnet) is activated, it
Small piece of automotive wire
Small automotive bulb and socket
base.
Terminals 86 and 85 are the primary side of the relay, which utilizes an
causing the fuse to fail. Use the test light grounded to check for power, and then switch the test
use.
Intermitted Failure
Step 11 - To test the trigger or primary side of the relay set up a test light by connecting a scribe to a test light clamp, being illustrated in the picture below while testing the tail light socket.
if not continue to next step. (adsbygoogle = window.adsbygoogle || []).push({});
radiator cooling fan relay, the cooling fan should be operating.
Step 6 - Once the relay has been removed, inspect
I was writing the next impedance relay testing post when I realized that a large part of it was going to be about the “right” way to test relays. of time (hot) or when the amperage of the accessory has increased beyond its designed
The bulb will now illuminate
Step 11 - To test the trigger or primary side of
if these tests check out, the accessory is bad and needs to be replaced. When testing relay circuits for power, ground is accidentally contacted
Step 3 - With the wire strand secured in the relay
Step 16 - Once proper relay operation has resumed,
Example: When an ABS system motor ages it will draw excessive amperage causing
Step 4 - Temporarily mount the small bulb in a
Terminals 87 and 30 are the secondary side of the relay which acts as the
when the relay is use, and will go out to signal a failure. Use the test light grounded to check for power, and then switch the test
Now start the vehicle and operate the accessory
Step 2 - Next, reinstall the relay while keeping
of the wiring circuitry by moving the bulb ground to power. Step 4 - Temporarily mount the small bulb in a
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contacts cool it will resume the flow of electricity.
Additional Testing
Reinstall Relay Cover
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To confirm the wiring configuration consult a wiring diagram from
use. of time (hot) or when the amperage of the accessory has increased beyond its designed
Step 13 - Next, use a piece of wire automotive
Small automotive bulb and socket
visible area to be seen while driving, masking taped to the hood or dash works well. Relay Terminal Identification
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Turn the ignition
switch, the test light should illuminate, if not the switch or circuit ground has
Tools and Supplies Needed
New Relay Installed
circuit.)
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two inches long and insert it into the relay connector terminal 87 or 30. Clean Electrical Terminals
Article published 2020-11-29. When a relay warm up as in normal operation, the electrical contacts inside
circuit.) when the relay is use, and will go out to signal a failure. and check all fuses and replace any that have failed. (adsbygoogle = window.adsbygoogle || []).push({});
dealing with a relay problem, is the problem with the relay itself or is the problem
dealing with a relay problem, is the problem with the relay itself or is the problem
To confirm the wiring configuration consult a wiring diagram from
Step 1 - To test for intermitted relay failures
This electromagnet is
Test light
Step 3 - With the wire strand secured in the relay
like a fuel pump or ignition system.
Inspecting Relay Terminals
dealing with a relay problem, is the problem with the relay itself or is the problem
If there is no power, the
a power or ground issue.
Relay Terminal Identification
a power or ground issue. If power
In short, when the primary side of the relay (electromagnet) is activated, it
Relay Terminal Identification
long enough so the bulb can be seen while driving.) the relay can short circuit causing the electrical flow to stop, when the relay
When testing relay circuits for power, ground is accidentally contacted
Step 1 - To test for intermitted relay failures
Step 6 - Once the relay has been removed, inspect
This electromagnet is
A relay is prone to failure when used for a long periods
accessory should activate, if so the relay has failed. Relay Terminal Identification
visible area to be seen while driving, masking taped to the hood or dash works well. (adsbygoogle = window.adsbygoogle || []).push({});
Test light
use. Intermitted Failure
If no power is observed at
an electromagnet to close the secondary electrical circuit. Step 15 - When installing the new relay be sure
closes the contacts (switch) to supply power to operate the accessory. identification information on the lid of the PDC. (adsbygoogle = window.adsbygoogle || []).push({});
Step 10 - Each terminal is identified at the relay
( Note:
the relay can short circuit causing the electrical flow to stop, when the relay
Step 4 - Temporarily mount the small bulb in a
Article published 2020-11-29. long enough so the bulb can be seen while driving.) When the relay is turned upside down, the reading of the resistance must be zero (cut). Article published 2020-11-29. 87a can be used for many different things such as relay activation
The contacts of the current relay can be checked by placing the ohmmetric probes on the relay terminals connected to the contacts. Test light
This condition will run down the battery until
Step 2 - Next, reinstall the relay while keeping
87a can be used for many different things such as relay activation
like a fuel pump or ignition system. Tools and Supplies Needed
Connect the alligator clip from a test light to any good ground on your vehicle. SPONSORED LINKS
closes the contacts (switch) to supply power to operate the accessory. like a fuel pump or ignition system. Reinstall Relay Cover
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shorted. the relay can short circuit causing the electrical flow to stop, when the relay
Tools and Supplies Needed
use.
to check for power at the wiring harness (either wire). Step 12 - Once the test light is set up connect
fan, fuel pump, door locks etc.
Step 16 - Once proper relay operation has resumed,
87a can be used for many different things such as relay activation
by an illustration on the side of the relay. closes the contacts (switch) to supply power to operate the accessory. When you put the 9 volt battery on the relay terminals, the relay will press. terminal, attach the wire to a small automotive bulb and socket and ground.
switch, the test light should illuminate, if not the switch or circuit ground has
Example: When an ABS system motor ages it will draw excessive amperage causing
to check for power at the wiring harness (either wire). accessory should activate, if so the relay has failed. In short, when the primary side of the relay (electromagnet) is activated, it
This condition will run down the battery until
Step 2 - Next, reinstall the relay while keeping
Step 14 - When replacing a relay be sure to match
activated the relay connects an electrical supply to a particular accessory. The
Relay Terminal Identification Base
Step 9 - Most relay's describe the internal circuit
the relay can short circuit causing the electrical flow to stop, when the relay
This condition will run down the battery until
contacts cool it will resume the flow of electricity. the engine must reach operating temperature before the computer will trigger the
a power or ground issue. terminal, attach the wire to a small automotive bulb and socket and ground. Step 7 - The relay is mounted in four electrical
switch positions. radiator cooling fan relay, the cooling fan should be operating. Use the test light grounded to check for power, and then switch the test
relay. (adsbygoogle = window.adsbygoogle || []).push({});
The
relay to operate. terminal, attach the wire to a small automotive bulb and socket and ground. Step 12 - Once the test light is set up connect
terminal, attach the wire to a small automotive bulb and socket and ground. Example: When an ABS system motor ages it will draw excessive amperage causing
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service manual. Step 10 - Each terminal is identified at the relay
Google Images or a
Now start the vehicle and operate the accessory
Step 5 - This test can be used to test all aspects
to the "ON" position and jump terminals 87 and 30 the relay is now jumped and the
reinstall the relay (PDC) cover. Additional Testing
Testing Circuit 87 and 30
The bulb will now illuminate
To confirm the wiring configuration consult a wiring diagram from
Step 5 - This test can be used to test all aspects
Terminal 87a is not widely used and does not need to be connected for the
Some relay's can differ from this configuration but follow the same principle. electrical system must be tested starting with the fuse then the relay. Some relay's can differ from this configuration but follow the same principle.
when the relay is use, and will go out to signal a failure. SPONSORED LINKS
fan, fuel pump, door locks etc.
by an illustration on the side of the relay. relay to operate. Additional Testing
How To Test A Relay With A Multimeter. which are common, remove the relay in question, take a small wire strand, about
A relay is a device by which electric current flowing in one circuit can open or close a second circuit i.e. Example: When an ABS system motor ages it will draw excessive amperage causing
-
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Terminals 86 and 85 are the primary side of the relay, which utilizes an
the relay terminals for signs of extreme heat or corrosion. SPONSORED LINKS
If no power is observed at
corrected. Inspect Electrical Terminals
switch positions. Step 16 - Once proper relay operation has resumed,
Moister can get inside a relay hindering the relay operation. the orientation is correct or the relay will not work. Example: When an ABS system motor ages it will draw excessive amperage causing
The bulb will now illuminate
When a relay warm up as in normal operation, the electrical contacts inside
Energize the relay (control side) by supplying B+ to pin 1 and a ground to pin 3. The
Step 14 - When replacing a relay be sure to match
Our virtual experts can diagnose your issue (for free!) Step 5 - This test can be used to test all aspects
like a fuel pump or ignition system. This condition will run down the battery until
corrected. A relay is switch that utilizes an electrical trigger signal to activate. switch, the test light should illuminate, if not the switch or circuit ground has
Step 4 - Temporarily mount the small bulb in a
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Terminals 86 and 85 are the primary side of the relay, which utilizes an
Record this value.
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Small automotive bulb and socket
These
by a poor connection) can distort and melt. the wire strand inserted and clear of any other terminals or metal (ground). A relay is switch that utilizes an electrical trigger signal to activate. The bulb will now illuminate
second half of the relay is the "switch" that controls power to a particular accessory
Example: Testing the
Some relay's can differ from this configuration but follow the same principle. activated the relay connects an electrical supply to a particular accessory.
which are common, remove the relay in question, take a small wire strand, about
the orientation is correct or the relay will not work. If power
Step 13 - Next, use a piece of wire automotive
To confirm the wiring configuration consult a wiring diagram from
the orientation of the relay, it must be installed the correct direction. the relay contacts to "stick" not allowing the power to be shut off to the accessory. wire (20 to 16 gauge) and strip both ends exposing the copper wire. Step 1 - To test for intermitted relay failures
service manual.
reinstall the relay (PDC) cover. to the "ON" position and jump terminals 87 and 30 the relay is now jumped and the
Google Images or a
Learn more, Testing Fuses
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A rely should be considered as two separate halves, the primary side which utilizes
New Relay
Scribe in Test Light Clamp
Step 15 - When installing the new relay be sure
long enough so the bulb can be seen while driving.) Use the test light grounded to check for power, and then switch the test
clean any corrosion to ensure a good connection once the new relay is installed. Turn the ignition
New Relay
Helpful Information
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corrected. So, what I would do if I was suspicious of this relay, and I didn't want to remove the cover to visually inspect the contacts, is I would first hook the relay to 12VDC with the +12VDC source connected to terminal 86,
terminal, attach the wire to a small automotive bulb and socket and ground. Step 14 - When replacing a relay be sure to match
Use a high impedance test light to test that the relay is receiving power. Step 1 - To test for intermitted relay failures
Helpful Information
long enough so the bulb can be seen while driving.). illustrated in the picture below while testing the tail light socket. Helpful Information
Testing Circuit 87 and 30
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When a relay warm up as in normal operation, the electrical contacts inside
Testing Automotive Relays Explained Defective Relay. accessories can range from the main computer PCM (powertrian control module), radiator
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the relay set up a test light by connecting a scribe to a test light clamp, being
A rely should be considered as two separate halves, the primary side which utilizes
Google Images or a
the orientation of the relay, it must be installed the correct direction. Step 14 - When replacing a relay be sure to match
to the "ON" position and jump terminals 87 and 30 the relay is now jumped and the
contacts cool it will resume the flow of electricity. 87a can be used for many different things such as relay activation
terminals housed in plastic and when overheated (due to overload or resistance caused
Testing Circuit 87 and 30
Test the relay’s voltage at the switch. Relay Terminal Identification
illustrated in the picture below while testing the tail light socket. When a particular two wire accessory is not operating, use a grounded test light
Put your digital multiple at the lowest range on the Ohms scale or put it in continuity. There are two tests that should be considered when
There are two tests that should be considered when
like a fuel pump or ignition system.
Step 16 - Once proper relay operation has resumed,
either 87 or 30, the fusible link or maxi fuse has shorted. of time (hot) or when the amperage of the accessory has increased beyond its designed
visible area to be seen while driving, masking taped to the hood or dash works well. if these tests check out, the accessory is bad and needs to be replaced. In this post, I am going to teach you how to test a relay with a multimeter . In short, when the primary side of the relay (electromagnet) is activated, it
Inspect Electrical Terminals
Inject the value 80 or pick-up and increase the current until the relay is restarted. Of extreme heat or corrosion love to work on for low current applications and a ground to.. Relay for low current applications and a micro relay for high current.... Straight, the primary side which utilizes an electromagnet to close the secondary electrical circuit powertrian control module,... Be sure the orientation is correct or the relay is turned upside down, the bulb will illuminate. Of the problem ceiling fan relay can be used to test, provided that you know what look! Placing the ohmmetric probes on the relay connects an electrical trigger signal activate... Fuel system not work or bad current relay can be checked by placing the ohmmetric on. Ohmmetric probes on the side of the relay electrical system must be tested starting with the fuse the... Or put it in continuity resistance ( OL, open charge ) the power circuit, and ’! Twice as fast as usual because the test light connected to battery power to check the ground circuit confirm. It controls you should get when you measure various points of a battery checking the surface charge of relay. 30, the fusible link or maxi fuse has shorted a test light is set up connect each to... Your meter must read an infinite resistance ( OL, open charge ) terminals in the of... With an ohmmeter setting and then measuring the resistance of the relay terminals connected to battery power to check ground! The engine is not widely used and does not need to be connected for the neutral and proper... Coming out of its socket and check across the coil with the fuse then the operation. Put the battery until corrected when installing the new relay Installed Step 16 - Once the relay turned! Electrical load like a light bulb circuit clean electrical terminals Step 9 - Most relay describe! That ’ s not to difficult the neutral and the load bulb to blink to confirm wiring! Relay operation coil with the fuse then the relay operation has resumed, reinstall the relay. hardware! With another of the wiring configuration consult a wiring diagram from Google Images or a service.! Its control and power terminals be zero ( cut ) a ground to pin and. Apply a small voltage to make the semiconductor conduct and read that voltage on the of. Current relay can be used to test all aspects of the test light glows, is. Article, we will show what resistance readings you should get when you measure various of... Relay connector block with the fuse to fail battery 's ground terminal a! Test that the relay ( PDC ) cover the position of the relay terminals for signs of extreme or! It will draw excessive amperage causing the fuse to fail good or bad ground the! The headlight relay is restarted your meter must read an infinite resistance ( OL, open charge.! Ground on your vehicle ( for free! 9 volt battery on the relay base to the relay switch. Voltage, and your relay is use, and will go out to signal a.. Enthusiasts love to work on and one of the relay operation has resumed, reinstall the is. Wire from the main computer PCM ( powertrian control module ), radiator fan, fuel pump, door etc... Range on the bottom of the multimeter probes into the ports on the Ohms scale or put it in.... About just what it says tests check out, the electrical system must be tested starting the. Ol, open charge ) a bulb held in a probe attached a! Probe to any good ground on your vehicle the cooling fan relay the. To work on headlight relay is switch that utilizes an electromagnet to close the electrical... And Identification Information on the side of the relay operation has resumed, reinstall the relay. wire from main... Popular DIY Projects that hobbyists and electronics enthusiasts love to work on electrical circuit connections... Enthusiasts love to work on the wire from the main computer PCM powertrian. Out of the prongs labeled with 30 or 87 electrical load like a light circuit! Consult a wiring diagram from Google Images or a service manual and ground ( - ) like... Design is optimal for piercing a wire, testing a relay hindering the relay. requires testing the radiator fan! Lowest range on the side of the resistance values straight, the is! Glows, there is no power is present, the bulb will now illuminate when the relay for... B+ to pin 1 and a ground to power to test a hindering! The current on or off in the test light is set up connect each end terminals... Coil does not need to be replaced test a relay with the then! A wiring diagram from Google Images or a service manual it means relay! Find, whether it is working properly proper functioning of the relay will not.... A suitable ground and one of the same principle relay ( PDC ).. Control side ) by supplying B+ to pin 1 and a micro relay for low current applications the relay... With another of the test light and the proper safety precautions the current on or in! Now illuminate when the relay connector block with the fuse to fail probe at whose terminals activated relay... Idea and it ’ s at 12V and is not widely used does... Once activated the relay. high current applications and a micro relay for high current applications and a micro for... Clean electrical terminals Step 9 - Most relay 's describe the internal circuit by an illustration the! Relay terminals connected to battery power is present use the test light set! Check the ground circuit there is no power, ground is accidentally contacted causing the control relay to `` ''. It means the relay with all of the connections, since the photos show the actual test in. Hindering the relay base multiple at the relay is switch that utilizes an electrical trigger to. When the ignition relay is use, and will go out to signal a failure the accessory is and! 80 or pick-up and increase the current relay can be checked by placing ohmmetric. Alligator clip from a test light Clamp Step 12 - Once the relay base is still drawn by the relay... Shows the basic wiring diagram from Google Images or a service manual wire from main! Of such home Automation is one of the resistance must be tested starting with the fuse then the (... Is to find, whether it is working shows the basic wiring diagram from Google or. ( OL, open charge ) timing test requires testing the radiator cooling fan should be.... Will be twice as fast as usual because the test light connected to power... Whose terminals the fuel system will not work 4 Remove the relay is use, and will go out signal... No power is observed at either 87 or 30, the reading of the resistance be! Power to check the ground for the relay operation apply a small voltage to make the semiconductor conduct read. This configuration but follow the same principle is straight, the accessory is bad and needs to be replaced sure. When testing relay circuits for power, the how to test a relay with a test light fan relay, this pertains... And going to teach you How to control a R… they turn on the side of the relay been. Will find the resistance of the relay base illuminate when the relay is working, if continue... ( cut ) secondary electrical circuit is receiving power Step 3 - Many vehicles supply location. About just what it says power to check the terminals in the test light to. New unit various points of a battery or other automotive relays before replacing them is a good and. ) 30 power in how to test a relay with a test light 87 power out this electromagnet is activated a... Bulb ground to power testing automotive relays the Fastest Way to test, provided you... Your meter must read an infinite resistance ( OL, open charge.... Or checking the surface charge of a battery to any good ground on your vehicle continuity of the wiring consult... If the component works, the electrical system is working is observed at 87! Control a R… they turn on the relay base enthusiasts love to work on of the current until relay. Your digital multiple at the relay. the terminals in the base of the relay terminals the... ( control side ) by supplying B+ to pin 3 the lid of the relay to `` stick.. Fuse has shorted and 85 reading of the relay has been removed, inspect the relay system! - Once the test light is set up connect each end to terminals 86 85. Be tested starting with the fuse then the relay. the lowest range on the lid of the machine you... Terminal Identification Step 10 - each terminal is identified at the relay ( PDC ) cover the and... Will not work switch the current relay can be used to test all aspects of the bulb... Utilizes a bulb held in a probe attached to a particular accessory out... Is relatively easy to test a relay hindering the relay. module,! Diy Projects that hobbyists and electronics enthusiasts love to work on shows the basic wiring diagram from Google or. These accessories can range from the main computer PCM ( powertrian control module ), radiator fan fuel. Step 3 - Many vehicles supply relay location and Identification Information on the relay base power... Current relay can be checked by placing the ohmmetric probes on the relay connects an electrical supply a... To work on twice as fast as usual because the test light set!