1977 power windows in op

[Mike D.]

Which fuse handles the power windows? Thanks.
Mike

[Mike T.]

Re: 1977 power windows in op

Mike - Just a guess here and nothing more but for midyears, they used a 'circuit breaker' instead of a fuse so maybe that's the same configuration for a 77?

[Richard M.]

Re: 1977 power windows in op

IGN must be on which activates the relay to supply power to the motor circuits via the switches. Here's a 74 PW diagram(same as 77).
1974PW.jpg
There is no "fuse" as mentioned as it uses a circuit breaker for main power.... But, with IGN on check for 12V at the Pink/Black wire at PW relay. Also ensure there is a clean ground on the relay case, maybe it's attached with a bolt to the birdcage in there somewhere. I'm not sure where it is physically located so you'll have to hunt for it. This Pink/Blk energizes the relay. This comes from the fuse panel and is noted on the 1977 wiring diagram(full pdf also attached below) as "Accessory Power" Note "P" on diagram. It appears there is a fuse for this but unsure it's location in the fuse panel.

Here's a slice I took from it....
1977Fuses.jpg

Org/Blk is a heavy gauge wire from the circuit breaker to the relay. Check for 12V there. If none, check CB for 12V on CB both studs. Red is its input from the Junction Block(firewall). If no 12V on Red you'll have to trace back to the source, likely the Main Harness. I'm unsure if there is a fusible link in that circuit.

The output of the relay is the Red/White, which should be 12v with IGN on. If you get 12v on Org/Blk, but not on Red/Wht with IGN on(after verifying 12V on Pink/Blk), then the relay is at fault.

Rich
PS also attached 1977 Wiring Diagram

[Mike D.]

Re: 1977 power windows in op

Thanks for the info. I appreciate it.

[Richard M.]

Re: 1977 power windows in op

Thanks for the info. I appreciate it.

Glad to try to help Mike. Please let us know what you found.

Rich