CRAZY Power window problem

[1984k20]

I have a 1978 K20 Silverado with factory installed power windows.
The driver side motor quit working. So I ordered a new motor & regulator assembly from “Parts Geek”. THAT was my first mistake.
They sent me an assembly for 1981-87 GM.
The regulator is the same, but the motor has a different electrical plug. It’s still a 2-prong plug, but it’s different. I had to source the correct plug from a friend.
After the install, the motor won’t operate off my truck’s electrical supply.
I might add that I don’t have any issue with the passenger side.
It seems as though the driver side wiring is not allowing the motor to have a ground to complete the circuit when pushing the switch.
The window will operate when I jump it with an old 12 volt Harley battery.
There’s nothing wrong with the switch, no breaks in the wiring.
I’m at a total loss.
I’m wondering if this newer model motor is wired up differently inside ?
Anyone here that can shed some light on this issue !
This is drivin me nuts !

PS.
I should say that I have both, a 1984 & a 1978 K20.

 

[Ricko1966]

The connector isn't just different the motors are wired different internally. Some use 2 hots 1for up 1 for down and use the case as ground. Others use 1 hot wire 1 ground wire and reverse polarity for up down.

 

[1984k20]

So is there any way I can get this new motor to work as OEM off the factory door switch ?

 

[Ricko1966]

So is there any way I can get this new motor to work as OEM off the factory door switch ?

Nothing easy,as in yes but it would not be worth the effort. Only way I can figure to do it would require 4 relays. I don't feel like drawing it up,but can if necessary. I'd recommend you buy the correct motor.

 

[bucket]

The connector isn't just different the motors are wired different internally. Some use 2 hots 1for up 1 for down and use the case as ground. Others use 1 hot wire 1 ground wire and reverse polarity for up down.

Yep, 2 hots was the early design. The reversing polarity type was the later design. Except for Suburban and K5 tailgate window motors, they kept the 2 hots design all the way through '91.

 

[1984k20]

I finally got this problem fixed.
Evidently my original issue was either a broken wire, or a faulty switch.
I tested the original motor that I removed earlier. It tested to be ok, so I reinstalled it.
I replaced the wiring (that had been spliced into several times in the past) with new wire. Took the switch apart & cleaned all the contacts.
It’s working now as it should. Although it’s rather noisy. I greased the gears & oiled all the pins thoroughly. So, I don’t get why it’s noisy. But at least it’s working now !
Thank you, for your advice !

 

[elimin8tor65]

I had an issue with mine as well. I would try to lower the driver window and the passenger side would move up. Also neither window would work most of the time. It started happening after I changed the driver side window switch. On mine, the plug that connectes to the switch has a cardboard type backing. While fixed the worn out back8ng I noticed the connectors were loose. Try wiggling the connector while moving the switches up or down. That's how I figured it was the connector that was bad.