Another Tailgate window woe

[Burbdually73]

Hi folks, first post. Anybody have a part number for a tailgate window switch relay?

Thought mine was shot and bought a HR151 relay and threw my old steel bodied relay away. Ended up being the switch giving me issues so cleaned and got it working properly. Now I have bigger issues and think it could just be the wrong relay. The window will work if the ignition is off but the minute I turn the key the relay clicks and I’ve got nothing. Turn the key off and still nothing. Remove the relay and reinstall and window works with the key off again. Checked wiring front to rear and even added a ground on the tailgate skeleton to the chassis, still no luck. Safety switch is bypassed and key switch on tailgate works fine. Any ideas?

 

[Tank6x2]

Found this in the forum…
Might help ya!

Power Window Relay Mod on Rear Window

A thought came to me while looking at the relay mod for the power windows in our square trucks. Could that same mod be applied to a power rear motor? It has an up, down, and off position on the switch just like the side power windows. You could pull 12V right off the junction block and splice...

www.gmsquarebody.com

 

[Tank6x2]

Guy did his own diagram

 

[Burbdually73]

Found this in the forum…
Might help ya!

Power Window Relay Mod on Rear Window

A thought came to me while looking at the relay mod for the power windows in our square trucks. Could that same mod be applied to a power rear motor? It has an up, down, and off position on the switch just like the side power windows. You could pull 12V right off the junction block and splice...

www.gmsquarebody.com

Thanks, I looked into that too. That’s next if I can’t get it sorted out

 

[gmbellew]

I didn't think any of the power windows had relays. you may check the wiring manual for your year.

 

[Burbdually73]

I didn't think any of the power windows had relays. you may check the wiring manual for your year.

I struggle to find anything. Found a k5 I believe, but no true luck

 

[Snoots]

???
I never knew, nor have seen, a relay for the tailgate window.

 

[Burbdually73]

???
I never knew, nor have seen, a relay for the tailgate window.

Mine had a steel bodied relay that looked factory. First square so not too experienced. After looking at this schematic I do notice something different in the wiring. I may try tonight to copy this. Hopefully it’s right for a 73 suburban

 

[Burbdually73]

There’s a large constant hot and the small pink ignition hot going to the 3 pin relay then to the switch.

 

[Burbdually73]

So I ditched all the BS going to the relay and ran the small pink ignition hot straight to the switch like the schematic above and everything appears to work as it should. Not sure what the previous owner had going on.

Connectors are from my trial and error experiments

 

[Burbdually73]

Any idea what the orange and black wire is supposed to be for? It’s a constant hot.

 

[gmbellew]

orange and black is for the key switch at the tailgate, I believe.

 

[Burbdually73]

orange and black is for the key switch at the tailgate, I believe.

Yup figured that out later on. What’s it go to or it’s function under the dash?

 

[bucket]

I bypassed the relay on my '78 so that the window switch on the dash would work at all times. All I did was plug a jumper wire into the factory connector for the relay.

I wish I would have done the same to my previous Suburbans. It's very convenient.

 

[Burbdually73]

I bypassed the relay on my '78 so that the window switch on the dash would work at all times. All I did was plug a jumper wire into the factory connector for the relay.

I wish I would have done the same to my previous Suburbans. It's very convenient.

Dang, so the relay is supposed to be there? Now I’m all screwed up.

Got any pics?