Hey guys I am new here so please be gentle. My 2004 Chevrolet Express 8 door Passenger van (doors on both sides) needed a real bad restoration. Rust spots and rusted out rocker panels. Fast forward 6 months and I was able to change out everything. Now onto the back passenger door. I cut out a piece of the door and was spot welding it back and the inside insulation caught fire. Nothing crazy but the wiring harness for the door lock, speaker and license plate light was toast. I have been to a few junkyards near me and found two wiring harnesses both with different number tags on them and only 6 wire (mine had 7, I’ll post it in pics) I was able to add a 7the wire to the new harness using the old one to match the wire colors up. I connected everything how I think they should have been but the rear door will not unlock or lock.

Does anyone have a schematic or a diagram of which wires go where? I cannot for the life of me find anything on this. I will attach some pics for reference. Thanks for any help!!!



Wires coming from up the pillar into the harness

Original harness




​​​​​​​

 

I hope this helps.
2004 Body electrical - Chevy & GMC Vans

 

Thank you so much for the diagram, it really helped tremendously!!!
So today I was able to get to the van and I connected the wires as suggested. I had to tap into the tan/black wire from the harness and run another wire to the two wire harness on the actuator which I believe is what allows the back lock and unlock all the doors in the van. So now with this wire jumped and going to the two wire harness I can lock all the doors from the switch but when I go to unlock the locks, all of the locks unlock but the back door doesn’t. Do I need to tap into the grey wire and then Connect a jumper wire to one of the other wires on the lock switch? If so which one? I have a light blue wire and a white wire, I was thinking of just taking a wire and see what happens but I don’t want to ​​​​​​pop a fuse or create a short. Thanks again for all the help!!!
here are the pictures of how I tapped into the tan/blk wire and ran another wire to the lock actuator.

 

that sounds backwards. According to the pinout tan is unlock, and grey is lock.
When you press lock, the computer applies 12V to grey through a relay. tan is grounded by default.
When you press unlock the polarity is reversed. Computer connects grey to 12V, and tan is already grounded by default.

I didn't know cargo doors had switches (I don't think mine does) but apparently it exists. That's what blue and white are. They just send signal to the computer that you pressed the switch.

Anyway, the wire colors should be exactly the same on both sides of the C400 connector. I think that all you need to do is connect the like colored wires.

I don't know if I would be using scotch locks with a high current circuit like door locks. They tend sever wires and create janky high resistance connections. I could see you ending up with another fire.
I would use these


or maybe use a barrier strip to replace the damaged plug. And that way you can unplug it if you need to do any work on the door. Or you can splice in a plug from the junkyard.

 

Hey thanks for the reply. I have a passenger van with rear passenger doors on both sides drive and passenger sides. As for the installation, Yeah I don’t really like the way the wires are all exposed I will probably redo them and put them in an insulation tape. As for the lock switch what is funny is that from the switch I can lock and unlock all the doors, the back door will also lock but it will not unlock while all the other doors in the vehicle are fine which is why I am thinking that since I jumpers the tan wire from the 2 wire housing and connected it to the tan that goes to the plug where the white and light blue wire is connected to, should I have to make a jumper wire from the grey wire and connect it to the white or blue wire as well? I hope I’m not confusing. I just am thinking that connecting the tan wire from the actuator and connecting it into the wire to the switch is what is making the back door switch work. Maybe I’ll try disconnecting the tan jumper and connect a jumper from the grey actuator to the tan switch to see what happens. I got the diagram of how the wires are connected into the harness coming from the car, but I can’t find a diagram of which wires are connected here at the door lock mechanism. Since the for I couldn’t tell what wires went where. Thanks for all the help! Truly appreciated!!!