complete dash harness replacement and the signal lights don't work

[Golden Boy]

i think i have that one as well. forgot about it! the one i was curious about is located on the left side of the dash and uses a male connector
i had to replace the door connector on drivers door as i broke the original one taking the harness out . the threads looked clean for a good ground. i should look at the pass side one tho. Again, Thanks for the help and interest!

 

[Golden Boy]

i have everything working except the door switched dome light/map lite( yellow wire circuit). the pink wire circuit works when i ground the double yellow w \black tracer pigtail with male bullet connector. don't remember this being plugged in to anything previously) been thru the wiring diagram several times and don't understand why it doesn't work. wonder what im missing here. gotta be something obvious that im not seeing? door switches have good grounds.

 

[FrankenKuda]

I made my own lighting circuit schematic. Both Exterior and Interior. Old Plymouth's use a lot of body grounds and only provide fused circuits to the devices. As mentioned before be sure the grounds on the switches and lamps have good paths back to good grounds. To make it bigger, I cut off the fuel gauge at the top and headlamps at the bottom. I did this to figure out my Low Fuel Lamp and other Consolette lighting circuits for my GC. I hope it helps.

 

[FrankenKuda]

GB, did you get this figured out?
I have my entire lighting system and dash sitting on a table and fully functional to include the delay timer. I'm not sure you have the delay in your car or not. I can remove it to verify things don't work any different without it.
Both the pink and yellow wires to the overhead dome lamp will have 12V on them when the door is closed or when the dimmer switch is not switched to the "overhead" position at the end of travel. The door ajar switch (yellow wire) provides a ground path when the door is open. I proved this today with my multi-meter. I have not checked, but I bet the dimmer provides the ground on the pink wire with the door closed and the dimmer switch is twisted to interior lamp.
Throw in the delay timer and a few other things get contributed. The delay timer yellow/black wire goes to the bullet connector with the two yellow wires (not the Y/BK one by the brake switch). You'll find this bullet connector up by the molded red block connector.
All the timer delay does, is provide 12V onto the M6 circuit for a few extra seconds. So if you have no dome lamp at all and everything else works. I'd think you are missing a ground path when either door is opened. I grounded both of my door switches but if you notice on the drawing you have the drivers side does not show the switch provides grounded. I'm pretty sure it does, I can check again tomorrow if you'd like. The passenger side does show switch ground.
Last thing. I also verified the dome lamp itself is a ground to the bulb. I'm not positive how this plays into everything, but be sure your lamp assembly also has a good ground path.