Power Window Relay

[Steve McMahan]

I’m in the middle of my 73’s restoration, and decided today was the day I would checkout some of the electrical components. Things were going great till I tested the power windows relay and got no contitivity between the center connector and ground:



First, just to check, I should have continuity between the center wire and ground? Assuming that is right, it’s a dud. And, sorry, $150+ for a replacement make me ask this question: can I use a more modern relay instead? I have one of those 6 fuse/6 relay sub panels, currently only using 2 or each. Can I wire this function into that box. And, what gauge (?) relay should I be looking for? I have a box or relays that came with that unit, but the OEM relay uses a very thick power feed wire, so I wanted to verify if I would need a higher Amp caring relay or ?

Thanks for the help, Steve.

 

[Don C]

The center connector should be the 12-volt input to the relay from the circuit breaker, via the black/yellow dot wire and will not show any connection to ground. The only one that should show a connection to ground is the connector with the purple/yellow hash wire, which provides the "trigger" from the fuse block and is hot with the ignition switch in run or accessory. The light blue with black dot wire provides power to the window switches when the relay is triggered.

 

[Steve McMahan]

When I test that connection to the case ground (clean, bare metal for the blade and the metal case), I expect to get a tone for continuity check. I don’t, but I do get like 65-70 olms reading (I didn’t notice that before). Shouldn’t I have free continuity through that electromagnetic device? Is that an indicator the coil may be week/bad? No previous experience in power windows or their circuits. Thanks for the help.

 

[Hemikiller]

Here's the 71 wiring diagram, it's much easier to read than the spaghetti drawings for 73.

Ground the case of the relay, and apply 12V to the spade terminals, one at a time. The one that causes the relay to close is for the Purple W/Orange hash wire. The other is the Lt Blue w/Black Dot output to power the system. Activate the relay and check for continuity between the center post and the output terminal.

 

[Steve McMahan]

Thank you.