The driver's side window on our '84 doesn't go down - the passenger window operates correctly. The driver's side window didn't get slower and slower before failing like I've read is often the case.

I followed the factory service manual to the extent possible (not sure how a guy can test the ground junction downstream from the passenger and driver's side switches meet without tearing half of the interior out!). I find power through the switch at more than 12 volts. I find power to the up and down leads just above the motor in the door at more than 12 volts, but barely. By comparison, I find almost 13 volts when checking the power leads for the rear hatch switch and other accessories also switched within the door. On what I believe is a related note, I note that the dash lights dim slightly when I operate the window switch in either direction and I hear (at least I think I can hear) a very slight hum from the area of the window motor within the door.

I'm reasonably certain that the window motor is toast, but I want to make sure I'm not missing something before I throw new parts in it. I've slammed the door while activating the switch thinking this might bump it along if there's a bad ground or the motor is hung up. Still no-go.

Also - probably coincidental - the hatch release switch in the door doesn't operate the solenoid. When I ground one of the switch leads directly to the battery it works perfectly. When I ground the other lead nothing happens - unless and until I activate the switch, at which time the solenoid operates correctly. I suspect a bad ground, not a bad switch. The hatch switch hasn't operated the solenoid for quite some time (but the one in the console does), whereas the window just quit working a few days ago.

Is there anything I should be doing before I order and install a new window motor?

How about the hatch release - what should I be doing with and about that? The ground lead runs through the interior light (which works) and disappears into the harness somewhere. I should mention that everything else in the door works correctly, even the wipers, which are high draw.

It's obvious, but I'll say that I don't know nearly enough about electrical systems and diagnosing problems and I really appreciate the advice.

Terry

 

I suppose you could unplug the motor and run 12v directly to it and see if it moves.

 

Thats next - just thinking I'd like to confirm the problem before I remove the glass and the mechanism. This can't be done while these are still inside the door.

 

Assuming you varified that it's not a broken plasic ribbon, and you're going to the trouble and expense of removing the window, I'd consider replacing the whole mechanism with the newer, and more reliable sissor type assembly. AFAIR, it's a direct replacement and just requires relocating a couple of mounting holes.

 

The hum that I hear is so low that I don't think it can be the motor working, loaded or not, so I'm fairly certain that the motor is done. I'll take your advice and replace the whole unit. EDIT: With a $300 price difference I can replace the motor and the plastic ribbon quite a few times - looks like time spent shopping may be well spent.

 

I hear you. Guess it depends on how much you value your time. Here's a re-manufactured one for a bit less:
http://www.ebay.com/itm/84-96-C4-CORVETTE-LH-DRIVER-SIDE-ELECTRIC-WINDOW-REGULATOR-REBUILT-/171310499148?fits=Model%3ACorvette

 

Thanks for the link. In a cursory search i found prices right around $380 plus shipping but i hadn't checked ebay yet. Thanks again.

 

It's much more likely that the plastic ribbon is broken. A VERY common problem. I have heard that the plastic ribbons in the HELP section for some other kind of car (Chrysler?) will work. I upgraded to the later window regulators years ago so I don't know the details on that. In any case, those ribbons are available from the usual Corvette parts suppliers.

You could try swapping the two switches in the console to make sure the problem isn't in the switch. I would take the door apart to see what's happening in there.

On your car the hatch release switch is grounded through the switch on the parking brake. The BRAKE light on the DIC must be on for the hatch release switch to work. All three hatch release switches use this ground, so if just the door switch doesn't work then the problem is localized to that one switch (and wiring).

 

My car has an automatic so I don't use the parking brake. The switch in the center console operates the release correctly without use of the brake, but I wonder if the door switch requires this? I'll have to check that. I don't find a door switch on the passenger side, but I gather that later models came so-equipped.

 

Good news - the car has been updated to the newer scissor style regulators already. I have a new GM OEM motor coming via ebay ($36 delivered) so I should be in business shortly. I haven't worked with the hatch release yet - too many other demands of my time lately.

 

I was looking at a wiring diagram for a manual trans. Sorry.

On my car the trans must be in Park or Neutral. The courtesy light module supplies the ground, so the courtesy lights have to be on. I don't know how '84s are wired.

Here's a weird one for you. On my car the button in the console gets its ground from the starter solenoid. I can't open the hatch if the starter is cranking (I tested that).

 

That is weird - I have to give it some thought. I don't see any obvious reason that it would be designed this way but it seems intentional.

Thanks for the help - I appreciate it.