Electrical Power door lock troubleshooting Foxbody

billison said:

Ok. Edit with details on what does what and how to check it.

It starts on the drivers side. A black with white stripe power wire. Constant ground from the circuit breaker (metal box) on the starter relay. If it does not have 12v check the cb and wires for a short.

2 black ground wires that ground to the door.

Then 2 pink wires, one with a yellow stripe and one with a green. These are the switched signal wires. Resting both are ground, when switched one is ground and the other is power. These wires run directly to the passenger harness where the magic happens. These 2 wires supply the ground for the passenger side and let the system work.

The passenger side has the pink/yellow/green wires from the drivers side and a pink with black and pink with orange wire. The pink/orange/black are what actually lock and unlock the doors, they go down into the passenger door to the actuator, split and run back over to the drivers side to the actuator. This side works the same as the drivers but instead of sending a signal to the other harness it goes to the locks.


How to test. Start simple , use a test light, test for power at the black/white wire on the 2 switches.

Then test to see if you get power to the pink/yellow/green wires when switchesd, if not, change or repair your switch. You can open the switches and sand /dremel the contacts clean. Do top and bottom . Don’t forget to test that the signal goes from drivers side to passenger.

After that, you have to unplug the actuator and use a meter or test light at the harness. Check 2 things. Check to see if you can complete the circuit ( power and ground) from The harness, if not, then check for ground at the harness using the 12v wire from the harness , then check for 12v doing the same. One Of these should lead you in the right direction. The






Seeing a bunch of these questions lately.

Basic details. 88. Both doors were swapped out. Replacement doors were both 87-93 but I didn’t document the years. Everything plugged up so I figured that was fine.

Here is what I’m dealing with. Driver side switch will do nothing. Passenger side will unlock both sides but that’s it.

Test so far. Used a test light to confirm power do both switches. Both send power to some of the pink wires but not all.

Test the passenger side with a new motor, no change.

At the passenger plug, power is present when I press both the unlock and the lock.

Used the test light to check for power flow across the switch and it would flow with unlock but not lock.

I believe I have a weak ground somewhere but don’t know how to properly troubleshoot. Normally I would just jump wires to find the issue but I’m not sure how to do that here.

Any help? Hoping to avoid all the testing.

Specificly how would I rule out the switch without ordering new ones?

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