1974 Power Window Problem

steve meltzer · 05-18-2019, 01:50 PM

I've owned the car for about 18 months and since day 1, the PW haven worked intermittently. Either all of the switches work, or none do. Thought at first I had bad switches so replaced both of the ones in the driver's door. Worked great for a few days, now, again, not at all. They can fail or work at the whim of the great electrical gremlin.
Here' s a picture of the fuse panel: There are fewer fuses and relays in extant, than the printed diagram on the panel's cover says there should be. So, i can't tell which fuse goes to the PW. Also, there is no relay for the PW. Car has no sunroof

This "all or nothing" phenomenon is unrelated to the door being open or closed.
The problem can't be in the switches nor the motors, and, as noted, I can't figure out which fuse it is. All of the fuses show continuity across them, and, tho' not really reliable, all "look good".

Not sure how much trust to put in my fuse panel, as the fog lights and horn relays are both opposite of the cover's diagram.
thanx again, steve

speedster911 · 05:28 PM

Steve,

There is a wire connector block in the drivers door that is the " junction Box" for all three window switches.

If your door panel has speakers, remove the Drivers door speaker and you should have access to it. Removing the entire panel is best. If your issue is erratic - sounds like a broken connection. I know my window switch issue drove me crazy - found a lose connection at the junction box.

steve meltzer · 05-18-2019, 05:26 PM

didn't even know it was there. gawd i hate taking that panel off, but it might be the best ?(only) option. thanx again. steve

eastbay · 05-18-2019, 06:58 PM

Not sure if you have done this, but on every old 911 I have owned I have gone through the fuse box and snugged up the screws on either side of the fuses. On every car there were some that were surprising loose. Sometimes it even cured a few issues.

speedster911 · 05-18-2019, 07:01 PM

Panel is easy to remove- if it is origina,l be carful as they they tend to be a bit fragigle at the connecting pin locations. Just take your time.

steve meltzer · 06:04 AM

First let me check the fuse panel screws and even replace the fuse I think is for the PW. But, the idea of a bad ground in the door would be a perfect explanation for this behavior. Novice question: Do the door pockets come off before and separate from the panel, or is it all one unit. I doubt these are original cards. More later. thanx. s

steve meltzer · 05-19-2019, 06:07 AM

Thanx again for all of the help. Do the door pockets come off before and separate from the panel or are they one unit? thanx steve

speedster911 · 05-19-2019, 06:55 AM

Door tops first. If I remember correctly: Then pocket lids, Pockets and last, the handels. Good luck

steve meltzer · 09:00 AM

Yippee...Just as eastbay opined, many of the fuse holder screws were in need of tightening, including the ones in the engine bay. While foolin' with the holder for the PW, the fuse was so loose, it just fell out and down into the the land of lost boys. After tightening those screws, I snugged up the contacts, installed a new fuse and viola (yeah, the musical instrument) my PW work perfectly. Thanx guys, I will have to learn about removing the door panel on another day!