SC window switch issues (79)

Robey5 · 09-16-2018, 06:08 PM

Hey yall:

I've been dealing with some bizarre issues with 79SC involving the window switch (driver's side, for the passenger window.) A couple weeks ago, I noticed that my passenger (power) window would not move using either window switches. The one ON the passenger side seems to move freely (window does not move though), but the switch on the driver's door-card for the passenger window had a stuck stalk.

After some searching, I decided that I would get the "non OEM" version of the switch, with the tin-plating on the wire connections on the back of the switch. Lesson learned, I suppose, but I believe that I have a little more going on here, because ....

The first switch I replaced had (has) the copper connection points, but the stalk will NOT move. I replaced with the new: and after about 10 minutes, and a bit of smoke, we've arrived at the same place: new switch, but another stuck stalk. Fuse did not get blown, and it seems that the stalk in the switch on the passenger's door card moves freely, and (after I pulled the switch on that side as well) all connections are solid and secure.

Earlier this season, I cleaned the window regs and the lubed the window lift mech, but I do not see any reason why this would cause this issue. ... anyone out there have any tips on where to look first? I guess I will buy another 3 switches; all the OEM type.....

Robey5 · 09-18-2018, 06:12 AM

Any thoughts on this?

walt · walt's Garage

I replaced several of my switches with non-oem and never had a problem . If you are getting smoke I tend to think a misplaced wire on the switch. Do you have a schematic to verify the connections are correct, unfortunately Pelican no longer has them on their website but perhaps someone can post it.

I would also apply 12V directly to the motor to verify it is ok.

brshap · brshap's Garage

I replaced my old non OEM switches (junk) with new OEM switches (slightly less junk) and it fixed my problems. Try an OEM switch and follow the advice above.

Also verify the wiring is correct. Some old posts on this site are not correct.

walt · walt's Garage

Not the schematic I was hoping to find but this might help.

78 911SC Wiring for Power Window Switch

Robey5 · 09-18-2018, 03:56 PM

Ok. Thank you for the link. I have a wiring diagram, and confirmed that the *correct* wires are on the switch, but I have not busted out the fluke to see if I have the right voltage present at each location.

To this end, I would be willing to bet that there is a ground loose in the door: is there a location IN SIDE the door that is a ground that I should be looking for?

Robey5 · 09-21-2018, 05:21 AM

For closure - I will update this thread/topic - I was able to determine what caused this issue and fix it last night.

On the driver's side panel - passenger window switch, I pulled the new (now broken) switch out and took another realllllll good look at the wires. It appeared that there was a crack in the insulation, and the red-white wire was putting bare wire on the red wire, and the result was a holy-smokes situation (literally) cooking the switch (rather than the car, thankfully).

The area that this was happening was a ways down the wire - away from the switch itself. Lesson learned. When you're working on a wire issue like this, get a look down stream. I am glad that we caught it.