Bobburt

I've searched all over and haven't found a solution.

My 1991 power door locks stopped working, sorta. The only recent addition I've done is added both dome lights. The Jeep didn't have any (no headliner or domes) when I bought it. Not sure if it's related. The locks lock like they're supposed to, no problem. But they don't unlock.

Circuit breaker in the fuse panel is good, all the fuses are good. The relays in the passenger kick panel click.

When I go to unlock them with either driver/passenger switch, the rear locks do nothing, the driver lock budges just a tiny bit, and the passenger lock very, very slowly turns over until it's unlocked.

I'm getting 12.5 volts to the relays and 12.5 volts to the passenger door switch when it's in its 'neutral' position. I noticed when I hit the switch to either unlock or lock position, I get a straight 10 volts at either relay. Is that normal? I'm kinda leaning towards new relays, but I just wanted to get a second opinion.

Bobburt

Bought a couple new relays and that didn't fix it. Acts the same as before.

Bobburt

Update:

Before I noticed my locks don't work, I had switched the courtesy lights to leds. So I went back and replaced both domes and kick panel lights back to regular bulbs just to see if that made a difference. No dice.

I then unplugged the dome lights completely. The front passenger lock now moves a bit faster, but still noticeably slow, and the rear passenger lock now actually moves, but still super slow. Strange that it makes a difference at all haha.

When I first checked the voltages at the relays, I didn't think to check both "out" or "ins" or whatever sets of wires. On the unlock relay, the "outs" are pink/black wires. If 12v power is on top, one set of pink/black wires would be left, and the other set would be bottom, imagine a + shape.

I checked both sets this time. Green is constant 12-12.5v. The left set of pink/black wires coming out of/into the relay hit 11v when I "unlock" which is normal compared to the lock relay.

The bottom set of p/b wires is different. When I unlock, that set only gives out 5.5 volts. So that's probably one reason why the locks don't unlock. Now I just gotta figure out where to go from here and what else to check.

Any additional input would be nice hehe.

Bobburt

Another update:

Locking still works like it should. Nice pow when hitting either lock switch.

Unlock still doesn't work. Whether the vehicle is running or not makes no difference.

RKE module in the ceiling is getting a full 12v to the pink wire.
Both dome lights get a full 12v from the pink wire.

Rear hatch actuator is getting 1v when switched to unlock, and 9v when locked. So the unlock voltage drop starts at the relay with 5.5v down to 1v at the back.

Went and checked any grounds I could find, all good.
Swapped out all relays I have into the unlock harness and no changes.

Can't for the life of me figure out how the voltage dropped from 12 to 5.5 at the relay out of nowhere. I didn't make any major changes to the electrical ever since I got the Jeep.

Bobburt

Did some more tinkering and noticed another strange thing. The light green wire that goes into both relays is constant 12.5v. When hitting either switch to the lock position, the light green wire dips to around 11.5v. But when hitting either switch to the unlock position, the same light green wire dips to 5.5v.

So both light green and pink/black wires from the unlock relay dip to 5.5v.

I read somewhere that when unlocking the doors, the lock power wires become ground for the unlock circuit, and vice versa. Is it possible that maybe the lock wires somewhere are stripped or in a door hinge touching the metal? I'm assuming the lock wires because if the opposite circuit becomes ground, this would mean that the unlock power wires are intact.

Could it be a completely snapped, or even a pinched wire somewhere? I haven't checked the wires in the door hinges yet.