1990 Bronco, niether side power door lock works, tried both switches, replaced 30 amp circuit breaker, if one accuator is bad will it prevent both sides from working? Lengthy replies and pictures welcome, thanks.

 

I have the same problem on my 95. Happened shortly after I bought it. I had a remote starter installed last year, and I was hoping they could make them work when they installed the lock and unlock feature. It still didn't work. They checked the actuators, and they both worked. I was told that I have a short someplace in the wiring, maybe right at the fuse box. I just haven't had the chance to investigate it any further.

 

The relay for the door lock circuit is weak and fails often. I replaced mine with one from an off-road light kit. You need to check the wiring diagram though for proper hook up. The best purchases I ever made were the factory service manuals.

 

The power for the door locks feeds through the passenger side assembly so if there is a problem with the passenger side it has the potential to affect the driver's side as well.

RanchRods,
Was unaware that there was a relay for the door locks, where is it located? May be a cool way to disable the locks when the truck is unattended... ya know, security thing.

 

Mine ('94) has the relay behind the glove box. But my old one ('88) had it under the dash.

 

Cool thanks!

 

Interesting. I'd suggest checking the ground on the passengers side. I've had a short in there around where the wires pass through the rubber sleve.

Good luck

Mike

 

Thanks for all the replies, didn't know there was a relay I'll try finding it and checking it out. Still wondering if one accuator goes out if it'll prevent the other one from working too, would greatly appreciate a reply to that question too.

 

I'm pretty sure thats not the case but I won't bet any money on it. Have you checked power to the switch on the passengers side? To me its a much easier start testing for power and a good ground. Good luck

Mike

 

I had the problem on my '96 and it turned out to be a lose wire that got yanked out of the plug by my fat foot. The door lock relay was under the dash right by the gas pedal and I guess I kicked it one day. I just stuck the wire back up in the plug and tie-wrapped it to some others in the bundle so it wouldn't come out, worked great.
You can get a complete service manual on CD over on Ebay for about $10. Good deal.



Mike

 

Thats not a relay! (No wonder I couldn't find it in the truck or on the diagrams). Thats the main wiring harness connector through the firewall. I thought this was fishy. I've spent a LOT of time with the door lock circuits working out security system options of my own design and I'd have taken advantage of any such relay.

 

The wiring diagram for my '92 has no mention of a relay.

 

Thanks again for the suggestions, going to pull the passenger side door panel this weekend, need to replace a speaker too, hopefully I'll find the problem. I also have a 91 F150 and and an 87 Mustang 5.0 CHP both with power door locks, never had any problems, I think the prior owner may have had a remote door locks set up installed, might be part of the problem, won't know 'til I take the door panels off, don't know who the prior owner is (bought it 3rd party) or I'd ask. Thanks a lot, Duane.

 

Well, guess what. I checked only to find out that the relays were installed aftermarket to accommodate keylees entry function for the alarm system. I must say that the install was so professional that I mistook it for a factory item. The relays were in a mounted retainer on the airbox behind the glovebox ('94) and on the lower dash support on my '88.

 

Just replaced my drivers side door actuator, it was weak and wouldnt lift my door latch up fully . This was not bad at all . In replacing it i opted to find out why my door light (courtesy)on my 1992 wasnt working.(Drivers side)U betcha, broken wire in the middle of the rubber where the wires run from the door to the main body.I tried unsucessfully to run a new wire in. No luck at this i put heat shrink on a #14 wire and cut a hole in the boot (each end) and fished the new wire in each boot ends, leaving the heat shrinked wire exposed along with the boot. Works great and the new wire is protected with heat shrink. On my actuator i had to drill out the rivet and used a #1/4-20 screw and nut. Finally light and power door locks work . Relay(actuator) , i though i was dreaming. i know my schematics rather well and didnt recall this either TR