Yukon Cargo Door locks??

[WisYukon]

Hey everyone. I'm a new owner of an old 1998 Yukon, 4 door 4x4 with rear barn doors. I have a couple of questions.
1) If I press the door lock button on the driver or passenger side, should that lock the barn door, or unlock if I hit the unlock button? I would think so but it doesn't work.
2) My key fob will unlock the cargo door, but won't lock it. From all the wire schematics I've looked at, the wiring to the actuator is the same as the rest of the doors. So how is it the keyless entry module can control one door (cargo) and not unlock the others? Is there a separate relay for the cargo door?

My problem is I can't lock the barn doors without physically moving the operating rod inside the door, and I can't unlock it with the door switches.

I'm stumped. Here's what I've tried so far: replaced the actuator. cleaned the plunger switches. Tested for voltage to the plungers and it get's 12v when I use the fob, but not with the door switch. I'm thinking it's not the wiring, it has to be a relay, or a connection somewhere. Any help?? Please!

Ben

 

[lesterl]

I would think it would Lock/Unlock all doors. If it is only getting the front doors you may have a bad relay or something...

 

[WisYukon]

The door buttons work with all 4 doors, just not the cargo doors. I would think relay too but the schematic shows only 1 relay and it is working for the other 4 doors. I wonder if there is an additional module or something that controls the cargo door, but I'm not seeing it anywhere.

 

[WisYukon]

So I've been trying to trace the wiring. I've found one connector behind the driver kick panel. I've also followed the wires from the cargo door, over the roof line, down the rear drivers side door frame and under the sill plates heading to the kick panel. There should be a connection somewhere for the lock side wire to connect to the front driver door actuator per the schematic. It would be helpful if anyone can confirm that the cargo door is supposed to lock and unlock with the door button, or only with the keyless remote. I'm beginning to suspect the keyless control module.

 

[lesterl]

My 95 worked all 5 lock motors from the door switches.....

 

[WisYukon]

Ok, so I'd assume 95 and 98 wouldn't change, except did your 95 have keyless entry? I think that's what is complicating things. There isn't much info on these keyless entry modules.

 

[lesterl]

My 95 originally had RKE, but I never had a remote....

 

[boyscout]

If the lock motor is good and it should be since you can open it with the remote I would question the grounds. I have had experience with another manufacturer and the lock issues were poor grounds. Motor would move the mech but not enough to engage or disengage them.

 

[lesterl]

Good thing this isnt another manufacturer..... Wiring can vary greatly from manufacturer to manufacturer as well as model to model in the same brand. That being said if the doors unlock with the keyless but you have one that doesnt with the interior switch, then I would suspect the keyless entry has a module that may be wacked out.....

 

[WisYukon]

I was thinking the keyless module too, since I think the relay that unlocks the cargo doors is part of the module. However it works fine to unlock the door so that kinda throws me for a loop on that theory. I'm pretty sure that there are several locations where the wires for each door lock, connect to each other and consolidate down to one, and then go to the relay/module. I'm trying to find where the lock wire for the cargo door connects to the rest, since it should lock with the others, I believe that it shares a relay for that function. Boyscout may be partially right, since the way the locks work, is by changing polarity to run the actuator in different directions. I'm going to keep posting my progress and hopefully this will help others when I figure it out. I'm surprised nobody else has posted with this problem yet.

 

[WisYukon]

I don't have the time or motivation to continue troubleshooting this. I think it's the keyless module, but I'm just going to wire the cargo door actuator to the passenger door actuator rendering the 2x button on my remote useless. It'll just bug me for a while wondering what actually was the problem. But I'll get over it LOL.

 

[lesterl]

Sounds like an excellent plan.....

 

[WisYukon]

just an update. The wire splice worked great. In my opinion, it should have been wired that way in the first place. I don't really need a separate button for the cargo doors. So in a nutshell, I pulled off the trim panel on the B? pillar, and the door sill on the drivers side. Found the Orange and Tan wires in the sill that go to the cargo door actuator. To be sure they were the right wires, I put a 9 volt battery on the terminals at the cargo door plunger switch. Then probed the wires with a voltmeter. Then I cut, and spliced them in with the orange and tan wires coming out of the rear drivers side door in the B pillar. Voila. The cargo door now unlocks like all the other passenger doors.