1992 Door Locks Inop
Thread Starter
Instructor
Joined: Feb 2015
Posts: 184
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From: Ontario CA
1992 Door Locks Inop
I am doing door panel repairs on a recently acquired 1992 coupe and one of the black wires on the door lock switch on the right door broke off at the terminal. I repaired the terminal and reconnected the plug to the switch and upon testing it the door locks were inoperative from either switch. I went to the auxiliary fuse panel and found the PWR DOOR fuse blown. I replaced the fuse with a fresh 15 amp fuse and it still did not work.
I'm at a loss for what to check next since the door lock switches worked correctly before I broke and repaired that wire. Thanks for any help you can provide.
I'm at a loss for what to check next since the door lock switches worked correctly before I broke and repaired that wire. Thanks for any help you can provide.
Last edited by Danlb; May 9, 2026 at 08:08 PM.
Team Owner
Joined: Sep 2003
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If you have the FSM check 8A-130-1 for diagnostic information and charts. I believe the first check would be if you have power seats, do they work? If they do, then it's assumed I believe that the Power Accessory Relay is good. If they don't start, there.
Do you have the FSM?
Do you have the FSM?
Melting Slicks
Joined: Nov 2016
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From: So Cal
2023 C4 of the Year Finalist - Unmodified
There are (3) black wires on the passenger switch. The (2) smaller ones are ground wires, these should be "ground" potential at all times. The larger black wire on the passenger switch is switched to (+) for UNlock, and remains at (-) for LOCK.
I think you may have mixed up where the black wires on the passenger switch are supposed to be when you repaired the terminal. At the passenger switch: The 2 small ground at all times are on B and E. The larger black wire that comes from B on the driver switch (use your meter to check for continuity to I.D. the wire) goes on D.
Thread Starter
Instructor
Joined: Feb 2015
Posts: 184
Likes: 36
From: Ontario CA
I was able to find the Power Door Lock schematic and it has helped understand how all this is laid out. As stated earlier I have no power at the orange wires on either switch. I checked the continuity from B to D and it is good. I checked the PWR ACCY circuit breaker at the main fuse block and it is good. I have power at one terminal of the location where the 15A PWR DOOR fuse plugs in on the AUX FUSE BLOCK #1 without the fuse plugged in. When I plug in the fuse I have 12V power at the test points on the fuse. I haven't been able to get to the back of the Aux fuse block yet to see if I dislodged any wires while replacing the blown fuse. Hopefully I can see everything a little better now that I have the passenger seat out. Do you happen to know how the aux fuse block is attached. Thanks for the help!
