Power windows are reversing polarity, meaning that at the motor one wire gets power and then other gets ground. When the switches are 'at rest' both wires should show ground. The motor does NOT provide the ground. Check the plug for the motor for ground, then move the switch and check for voltage. You can trace the wiring in the door rather easily since it is already apart to check for breaks. It does sound like the switch may not be giving the ground for the circuit.
Going off my foggy memory, I believe the spring threads through a hole in the plastic housing and needs to be grounded(which I believe the silver bracket provides). The silver bracket gets sandwiched between the wheel and the adaptor. If you can't get it to go back together you can save yourself some aggravation and get a horn button for a Grant GT wheel.
You can get the codes by cycling the key and reading the flashing light on the dash. Search here for the codes and procedure: https://www.turbododge.com/
I believe each of the infinity speakers has an onboard amplifier. With an aftermarket radio you may be overpowering those onboard amps causing it to cut out.
I was gonna add another I saw in the junkyard but it's on the list, 201060. One seen another one locally but didn't get to meet the owner, yellow/ginger/? 202094
I will add mine. ZC2FP1106KB201199, 1989 SOHC Royal Cab/ Ginger/ Black.
I also grabbed some parts off a 1990 in lkq vin ZC2FS1204LB205024. It was red/ginger/black.
Found a youtube video that shows how the Teves systems work. It is an old Chrysler tech video that helps to understand what's going on. It mentions an accompanying tech manual/reference book that I will try to find a pdf of to post.
You should get yourself a service manual. I don't have one in front of me, but there is an access plug at the back of the caliper that you need to remove. There is an allen head adjuster that you will need to turn to retract the piston. Other members should be able to add more detailed guidance.
Do those parts come with the bracket on the glass? The brackets kept popping off on my old window before it broke and the replacement from LKQ is a little ratty.