D350 truck power window gremlin

[pmschmitt]

Ok I purchased an 83 D350 crew cab with power windows and locks in the front and manual in the rear. Both power windows were inoperable at purchase as were the locks.

I pulled the regulators and motors the drivers side motor was toast. I rebuilt both motors and replaced the drivers side regulator that was binding ( probably caused the motor to fail). I reinstalled and checked the function of both motors and windows with an external 12V source, both worked fantastic. Now on to the wiring .i have checked both switches with an ohm meter and they appear to be working correctly transferring current. The drivers side window works, but the passenger side will not. Here is what it is doing:

The following are the voltage readings atthe wires going to the motor on passenger side

Drivers side switch up
VT-WT wire 1.6V
PK-WT wire 10.3 V

Drivers side switch down
VT-WT wire 10.3V
PK-WT wire 1.6V

Passenger side switch up
VT-WT wire 12v
PK-WT wire 12v

Passenger side switch down
VT-WT wire 12V
PK-WT wire 1.3V

I know this is a c body forum, but talks expertise and all things wiring is why I come to you. Once I get the wiring sorted I plan on adding relays . All help appreciated seems the same voltage out of passenger side switch up is abnormal. I have attached a wiring diagram from FSM and pictures

 

[Big_John]

Passenger side switch up
VT-WT wire 12v
PK-WT wire 12v

My guess is the passenger side switch is bad, based on the voltage readings.

Based on what I've read about checking my own switches, and I believe these work just the same, if you took the switch off, you should be able to run a jumper between the upper left connection (PK) and the lower right connection (VT) and then a second jumper between the center (TN) and the lower left (PK/WT) and the window should go down.

To make it go up, jumper between center (TN) and upper left (PK) and jumper between lower left (PK-WT) and lower right (VT)

I may have those switched (up versus down) but that will bypass the switch. If the jumpers work, it's the switch.

 

[pmschmitt]

Thanks big John I just purchased the passenger switch off eBay as NOS .. but who's to say. I will check the jumpers

 

[pmschmitt]

So I got the drivers side working and controlling the passengers side window, but the passenger side switch would never control the passenger window. I planned to take the new NOS switch apart to check the contacts and...... blam the old plastic casing disentigrated into 5 peices. Such is my luck