67 Power Windows Problem

[Jeff B.]

Seeking advice on trouble shooting power windows issue. Went to a car show last weekend. Got to show and put windows down. Everything worked fine. Judges came by for operations check, and neither window would go up. Both were "dead" in the down position. Drove back home and still neither window would work. Just like there was no current to the windows. All fuses on the fuse block tested good. Where do I start diagnosing this problem?
Have owned car (built in January of '67) for 45 years, and never an issue of any kind.
Any ideas wholeheartedly welcomed.
Jeff

[Mike T.]

Re: 67 Power Windows Problem

Jeff - Did you happen to notice if the needle on the Battery Gauge moved at all while trying to push on the window switch?
If not, maybe just a bit of corrosion on that switch under the dash.

[Leif A.]

Re: 67 Power Windows Problem

There is a self-resetting 30 amp circuit breaker on the left side kick panel. With power windows, you'll have two of them...one for the headlight motors and one for your power windows. It's possible it has given up the ghost, as it should automatically reset.

[Richard M.]

Re: 67 Power Windows Problem

Also, 1967 was the first year that required Key RUN or ACC for the windows to work. There is a relay next to the CB at the left kick panel that has possibly failed, or the feed wire from the ACC circuit to activate the relay has open circuited.

I have a 1967 PW wiring diagram I'll drop here later which may help. Chevy never had a accurate '67 Corvette version. Theirs was a generic Pass car diagram.

Rich

Edit.... Here's the diagram and a few corrected 1967 A31 AIM pages. Obviously no rear windows in a Corvette so ignore that and the master switch configuration.

First thing you may want to check is the big Red wire which plugs into the fuse panel. If that's unplugged, easy peasy fix. (see below)

There is also the Brown(ACC) circuit wire which plugs into the A31 harness under the dash. This is the power to the relay coil. It may be in a 3 way plug if you have a radio with it's capacitor in the circuit too. If that's unplugged, also easy peasy fix. (see below)

Mike's idea about seeing if the BATTERY gauge flickers will also be a clue. 2 steps though. Watch it when Key to ACC. Keep radio and heater off. If it flickers, and you might hear it clicking in a quiet garage(put your hear next to the kick panel), that means the relay may be getting power to activate the coil inside it. But if the high current contacts inside the relay are bad, it won't bring power to the console switches.

If it flickers when you move the switches it's indicating they're functional but not getting power to the motors. Unlikely both motors are bad unless somehow both window motors grounds opened. Unlikely... but possible.

Based on your observations it could be the relay or CB or the wiring, but best way to diagnose is a test lamp or voltmeter at the various circuit paths. The relay is used to simply switch the main feed power from the CB to the switches to power the motors as you'll see in the 1967 diagram. All prior years with PW didn't need key on.

1967_PW_Wiring DiagCropped.jpg

1967_ACC_BrownWire_A31Wiring.jpg

1967_ACC_BrownWire_Wiring.jpg

[Jeff B.]

Re: 67 Power Windows Problem

Thanks for all suggestions.
Mike - The ammeter does not flicker at all when either power window switch is moved.
Leif & Rich - I plan to start testing for voltage, beginning at the pwr wdw plug-in on the fust block, and work out towards the relays and circuit breakers. When I find spot where voltage disappears, I should find my problem. Just wanted to make sure I was testing circuits in the correct sequence. Will keep everyone posted on progress.

[Jeff B.]

Re: 67 Power Windows Problem

Rich:
Am somewhat confused regarding the fuse block plug-in spot for power windows. My car has been untouched under & behind dash for over 40 years, and never a problem of any kind. Never even an occasional blown fuse. On the bottom right corner of the block are two plug-ins. Under them is the wording "power windows". I have only one red wire, plugged into the right one just above "windows". Yet I understand this wire should be plugged into the one on the left above "power". I have tested voltage at both plug-ins, and both are hot. Switched the red wire to the left one, and windows still do not work. Suppose next check is relay and circuit breaker? These both are behind left kick panel?
Thanks again for your input.

[Leif A.]

Re: 67 Power Windows Problem

Jeff,
Pictures of where the circuit breaker is located. Note the courtesy light as reference...just above the left kick panel carpet. Second picture shows the two holes that secure the circuit breakers. Upper hole is for the headlight rollover motors. Lower hole is for the power window circuit breaker.

[Richard M.]

Re: 67 Power Windows Problem

Perfect..... Thanks Leif. Just heading out to dinner.

Jeff both of those are constant 12v so either one
Yes check at CB, then relay Red wire. With key RUN you should get 12v on the Brown and the Red/White wire. If Brown and Red are 12v, and 0v on Red/White..... bad relay.

Edit1... the relay is in the same area. Tight in there though. Also make sure it's tightly mounted. It uses the birdcage for ground.

Edit2... Well, She's still "Processing", so here are a few photos of the relay and Brown ACC wire with PW...

PW_Relay_P8070042.jpg

The PW harness has a dual receptacle. The Brown of the main harness and the Radio Capacitor plug into it.
P8070049.jpg

That relay above the plugs is for the Speed Minder speedometer on this car.
P8070048.jpg

Rich

[Jeff B.]

Re: 67 Power Windows Problem

Rich:
Testing indicated circuit breaker defective. Jumped the breaker and everything worked. So to replace the breaker is next on list.
Thanks again for your narrative and excellent pictures.
Jeff

[Richard M.]

Re: 67 Power Windows Problem

Good work. Good troubleshooting. Leif called that out in post 2.

I've rarely seen them fail. It's possible the terminals are corroded causing a open.

I'd remove both Red wire terminals. Note which is which as there's a BAT terminal and other side is the load. One stud is taller than the other. One is BAT(Edit... the SHORT one) and comes from the fuse panel plug. Load Red goes to the relay.

Test across the clean area of the studs with a ohmeter or test light. If open, yes it's bad.

So if it tests bad you can open it up to see the fault. May be a simple fix by carefully filing the contacts.

[Richard M.]

Re: 67 Power Windows Problem

I had this C1 power top circuit breaker in the bin and recalled I took it apart to have the case plated. So I took a few photos. There are 4 little depressions in the case to hold it together. To open it up use a small pick to open them away from the bakelite insulator base.

Here are some shots of the internals and how simple it is.
20231107_143712.jpg20231107_144114.jpg

The short stud shows "BAT"(Input). Long shows "AUX"(Load).
20231107_144031.jpg20231107_144058.jpg

The bimetal strip inside. When too much current passes through the contacts, the metal strip heats up and its contact raises away from the base contact.
20231107_144131.jpg

Here you can see the 2 rectangular contacts.
20231107_144146.jpg

Toothpick placed between the 2 contacts, emulating what happens when it exceeds max current rating and opens. This one is 30 Amps.
20231107_144217.jpg


20231107_144318.jpg

Those rectangular contacts may need cleaning, or the terminal studs have some corrosion. Since originals are unavailable and replacements are differently configured, it's often best to repair your original. Pretty simple electrical part.

Rich

[Jeff B.]

Re: 67 Power Windows Problem

Rich:
Thanks again for your input and pictures. Haven't yet attempted to locate a replacement CB, but will try your suggestion to disassemble the original breaker and "repair" if possible. Will be this weekend before can do so. Am wondering if the operations judge tried to run both windows up at the same time?
Really appreciate your help.
Jeff

[Leif A.]

Re: 67 Power Windows Problem

Rich:
Thanks again for your input and pictures. Haven't yet attempted to locate a replacement CB, but will try your suggestion to disassemble the original breaker and "repair" if possible. Will be this weekend before can do so. Am wondering if the operations judge tried to run both windows up at the same time?
Really appreciate your help.
Jeff

Why was a judge operating the windows (or, anything else for that matter) on your car? You're supposed to showing how everything works. Judges aren't supposed to touch your car.

[Jeff B.]

Re: 67 Power Windows Problem

Why was a judge operating the windows (or, anything else for that matter) on your car? You're supposed to showing how everything works. Judges aren't supposed to touch your car.

Leif:
This was not an NCRS sanctioned show. Was sponsored by a local Chevrolet dealership with about 250 cars (all brands) attending. Didn't know any of the judges nor their qualifications. Don't know how he activated the windows, except they didn't go up. First show, for me, where operations were tested, and didn't know the "rules". I'm not upset with the judging, but now know what is allowed and not. The CB malfunction just could have been a coincidence.
Thanks for your clarification. I will know better next time.
Jeff