Door lock switch puzzler

[CharlieS]

My passenger door lock has an odd behavior where I would be appreciative of input from the 'mud crew.

What does not work: Unlocking the passenger door from the passenger door lock switch.

What works:

1. Locking the passenger door from the passenger door lock switch
2. Locking the passenger door from the driver's side master door lock switch
3. Unlocking the passenger door from the driver's side master door lock switch
4. Locking the passenger door from the driver's side exterior key/lock
5. Unlocking the passenger door from the driver's side exterior key/lock

Seemed like a no brainer, the passenger switch lock side is hosed. Replace the switch. So I did, I got a used switch from a trusted vendor and swapped it in. No change in behavior.

This leads me down the road of a potentially broken wire(s) or loose pin(s)/connector(s) between the switch and the actuator. So, I need to do some troubleshooting.

Has anyone seen anything similar? Any troubleshooting steps? Or other ideas/thoughts? Any tests that I could do from the switch end before pulling off the door panel.

 

[wileetoyote]

My passenger door lock has an odd behavior where I would be appreciative of input from the 'mud crew.

What does not work: Unlocking the passenger door from the passenger door lock switch.

What works:

1. Locking the passenger door from the passenger door lock switch
2. Locking the passenger door from the driver's side master door lock switch
3. Unlocking the passenger door from the driver's side master door lock switch
4. Locking the passenger door from the driver's side exterior key/lock
5. Unlocking the passenger door from the driver's side exterior key/lock

Seemed like a no brainer, the passenger switch lock side is hosed. Replace the switch. So I did, I got a used switch from a trusted vendor and swapped it in. No change in behavior.

This leads me down the road of a potentially broken wire(s) or loose pin(s)/connector(s) between the switch and the actuator. So, I need to do some troubleshooting.

Has anyone seen anything similar? Any troubleshooting steps? Or other ideas/thoughts? Any tests that I could do from the switch end before pulling off the door panel.

I assume the PS mechanical lock/lever next to the inner door handle is properly moving back and forth using the DS master lock which would rule out the door lock actuator itself. If that is the case then I agree with your assessment of a bad connection between the PS switch and the pin on the door actuator connector. I would ohm out the wire from the PS switch to the actuator and look for a break or it may be an oxidized pin on either side connector which you could scrape clean.

I just replaced my rear passenger door lock actuator and in my case, the actuator would unlock properly where the mechanical switch would move to the unlocked position (from locked) but when trying to lock it from either the DS or PS switch, it mechanically wouldn't move/lock. I tried to clean and lube all the mechanical linkages which were binding pretty badly but that didn't help, replacing the actuator fixed my problem.

Do you have the FSM wiring diagram?

 

[LandCruisinMy93]

My passenger side had a similar issue with the power window and door locks. It worked and then it wouldn't and then it would. I ended up figuring out the harness at the door jamb had a break. I pulled some slack from the cab into the door and it all worked again. I ended up getting a different harness from the salvage yard and swapping it out.

 

[CharlieS]

I assume the PS mechanical lock/lever next to the inner door handle is properly moving back and forth using the DS master lock which would rule out the door lock actuator itself. If that is the case then I agree with your assessment of a bad connection between the PS switch and the pin on the door actuator connector. I would ohm out the wire from the PS switch to the actuator and look for a break or it may be an oxidized pin on either side connector which you could scrape clean.

I just replaced my rear passenger door lock actuator and in my case, the actuator would unlock properly where the mechanical switch would move to the unlocked position (from locked) but when trying to lock it from either the DS or PS switch, it mechanically wouldn't move/lock. I tried to clean and lube all the mechanical linkages which were binding pretty badly but that didn't help, replacing the actuator fixed my problem.

Do you have the FSM wiring diagram?

You are correct, the manual portion of the lock does move as expected when locking and unlocking from the master switch, door lock cylinder on the drivers side, and it moves to the locked position when using the passenger switch. The mechanical portion doesn't move when pressing the unlock directional of the passenger lock switch (both original and replacement).

Time to pull the door card.

Thanks!

 

[CharlieS]

My passenger side had a similar issue with the power window and door locks. It worked and then it wouldn't and then it would. I ended up figuring out the harness at the door jamb had a break. I pulled some slack from the cab into the door and it all worked again. I ended up getting a different harness from the salvage yard and swapping it out.

I'll dig into that. Thank you.

 

[CharlieS]

Oops, missed replying to a question: yes, I do have the FSM/EWD.

 

[landcrshr]

Sounds like you need to troubleshoot why the UNLOCK signal from the passenger door isn't getting over to the controller in the driver door.

 

[CharlieS]

Some info from the FSM that may help me or others in the future:

 

[CharlieS]

 

[CharlieS]

Okay, so this story has a happy ending.

@landcrshr - winner winner, chicken dinner. You nailed it.

First let me say that I failed to give a relevant fact (because I didn't know that it was relevant). That fact is that this 80 has had a lot of body parts replaced by the prior owner, including the passenger front door.

What I found through lots of testing of wires and connectors was that all of the individual segments of wire had continuity when broken down, but there wasn't end to end continuity when all of the connectors were plugged in from passenger door switch to driver door relay.

What I eventually found was that the "unlock" wire location on the passenger kick panel multi pin connector male pin was not lined up with the female side. The unlock signal was getting interrupted.

So I depinned the wire (blue/yellow) on the male connector (body side) and moved it to the location that would line it up with the female (door side).

I could have done it the other way (and maybe should have, maybe will...), but for diagnostic purposes, this solved the unlock problem. The door now locks and unlocks as expected from the passenger door switch.

My theory (not researched or validated yet) is that this door and it's wiring harnesses came from a different year and although the connectors physically fit together, the wires aren't all in the same pin positions.

Anyhow, now to put it all back together. It took a fair amount of disassembly to test the harnesses and connectors from the passenger door to the driver door where the door lock relay lives.

Thanks all.

 

[landcrshr]

Okay, so this story has a happy ending.

@landcrshr - winner winner, chicken dinner. You nailed it.

First let me say that I failed to give a relevant fact (because I didn't know that it was relevant). That fact is that this 80 has had a lot of body parts replaced by the prior owner, including the passenger front door.

What I found through lots of testing of wires and connectors was that all of the individual segments of wire had continuity when broken down, but there wasn't end to end continuity when all of the connectors were plugged in from passenger door switch to driver door relay.

What I eventually found was that the "unlock" wire location on the passenger kick panel multi pin connector male pin was not lined up with the female side. The unlock signal was getting interrupted.

So I depinned the wire (blue/yellow) on the male connector (body side) and moved it to the location that would line it up with the female (door side).

I could have done it the other way (and maybe should have, maybe will...), but for diagnostic purposes, this solved the unlock problem. The door now locks and unlocks as expected from the passenger door switch.

My theory (not researched or validated yet) is that this door and it's wiring harnesses came from a different year and although the connectors physically fit together, the wires aren't all in the same pin positions.

Anyhow, now to put it all back together. It took a fair amount of disassembly to test the harnesses and connectors from the passenger door to the driver door where the door lock relay lives.

Thanks all.

View attachment 3641909View attachment 3641910

Glad it was a simple fix!