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Short version: on my 74 coupe the drivers side power window motor died.
What is best source for replacement motors? Is it still Willcox? I'm trying to avoid getting a new ones that others have had bad experience with.
Also, Since the drivers side has died, I anticipate the 47 year old passenger side motor will die soon too.
I see some pictures of c3 doors (an example by a vendor, i think) where the inner frame was removed to get a look at guts of door. I noticed a ground wire for the window motor. Was that stock on some years? Or was that someone adding an insurance policy?
Now for the details:
The regulators/wheels/springs/anti rattles/inner and out felts have been rebuilt.
All electric has been tested: switches, wires, relay, power source. Even ground connections where motor attaches to regulator, and regulator attaches to door.
When the window mechanism were rebuilt earlier this year, the 46 year old window motors worked unbelievably fast. But then drivers side motor died. Then my research showed that a soon-to-die-motor may work much faster than normal. The fast-up/fast-down excitement was short-lived.
Thanks @SwampeastMike , that's precisely the experience I was looking for. Here's two updates since i posted this question:
1. Curiosity got the better of me and I took apart the case (not the whole motor, just the case) and cleaned it with compressed air and CRC. It was full of black dust. I learned the dust is the remains of the brushes. Further investigation showed the braided copper wire for the positive side brush was disconnected from the brush; hence the issue. BUT all research on the forums showed that it's not worth the effort to do the repair or replace the brush, because something else could go wrong. Sooo.....
2. I went ahead and ordered from Willcox. Both motors. Because I'd like to minimize the chances of needing to open the doors up again to do this job.
I should have replaced both of my power lock actuators while in there instead of just cleaning and lubricating them. The passenger side is now too weak to unlock half the time so back into the door with its nicely installed vapor/sound barrier.
I presume you know you can use a bolt and stop nut (with the nylon insert) in place of the large pop rivets.
A window that goes down very quickly but up more slowly is the result of a broken assist spring which in turn causes great stress on the motor.
Are you certain that the motor is 'dead'? Have you checked for voltage getting to the 2-connector plug going to the motor? (one pin on that plug is for UP 12vdc; the other is for DOWN 12vdc: motor ground is a separate black wire.) Most window failures like yours are due to bad switch contacts, broken wires, bad fuse, etc.
Last edited by 7T1vette; Dec 19, 2020 at 04:35 PM.
@Bills17n72 , thank you but no. I have ordered 2 from @Willcox Corvette @7T1vette , yes, all wires, switches, relay, grounds, were tested and confirmed. Mechanisms rebuilt and greased, springs replaced. @67:72 , thank-you, that sounds like a good source too.
I'll reply back with how the new motors perform when I put them in.
Two nearly identical 78’s; in one the windows go up and down surprisingly ast; the has a slow window on the right, a slower window on the left. Completely rebuilt everything in the doors with a new motors. The slower one already had a replacement motor, as evidenced by no rivets. Replaced all the nylon wheels and cleaned regularly-lubed the channels. Neither window moved any faster than it did before, but I am reassured everything works good enough.
Rattles from in the doors have always annoyed me, so I used a couple extra foam anti-rattle pads along with zip-ties to quiet them.
A piece of Dynamat on the inside of the door skin augments the insulation inside the panel nicely. Nice thunk sound closing the doors.
"Slow" windows are usually caused by window switch contacts which are burnt/corroded. That junk on the contact raises the resistance such that significantly reduced current actually reaches the motor. Remove the switch (clearly recording the location and orientation of each switch), pry back the swedged areas on the housings, CAREFULLY remove the guts (there are springs in there!). Then clean the contacts and put some non-conducting electrical grease on them to prevent arcing. Reassemble the switches and install them. Windows should be much faster.
"Slow" windows are usually caused by window switch contacts which are burnt/corroded. That junk on the contact raises the resistance such that significantly reduced current actually reaches the motor. Remove the switch (clearly recording the location and orientation of each switch), pry back the swedged areas on the housings, CAREFULLY remove the guts (there are springs in there!). Then clean the contacts and put some non-conducting electrical grease on them to prevent arcing. Reassemble the switches and install them. Windows should be much faster.
Thanks for the tip on switches. To start I timed the windows up and down. Driver side 6-7 seconds, then died partway up! Pass side 5 sec..
The driver side switch had previously been replaced. Pass side had previously been pried open and a plastic shield installed above the contacts to keep stuff out. The plastic shield had was scorched near the contacts from arcing. Cleaned up the switches and put them back in. Happened to have a new switch on hand to compare function. Pass side went to 4 sec up and down (20% better). Driver side got the old switch to do a solid 6sec. New switch was no faster. Going up feels like it takes off quick at first and hits resistance 3-4inches up; like something in the mechanism that isn’t exactly where it should be is binding something. By comparison the other 78 has a 3 second driver window, 4 seconds for the pass side (time to clean that switch). Driver side, pass side, new Driver-I think that fir needle was not enhancing conduction Pass side with scorched plastic shield pass side- the shield kept a bit of stuff out of the actual switch contacts
If you clean everything up, get all burning and corrosion off the contacts, put dielectric grease on those contacts and re-assemble them, you will likely find that the window motors operate quite well.
P.S. Checking continuity of switches and power line using an ohmmeter is fine...but it doesn't determine how much current flow would be restricted when significant current is trying to flow thru that system. You need much different equipment to find and quantify those kinds of electrical problems. Complete motor windings are very low resistance components. So burnt switch contacts could eat up significant current and convert it to heat for a few seconds when the switch is 'made'. That's the scorching you see inside the switch housings.
If you clean everything up, get all burning and corrosion off the contacts, put dielectric grease on those contacts and re-assemble them, you will likely find that the window motors operate quite well.
P.S. Checking continuity of switches and power line using an ohmmeter is fine...but it doesn't determine how much current flow would be restricted when significant current is trying to flow thru that system. You need much different equipment to find and quantify those kinds of electrical problems. Complete motor windings are very low resistance components. So burnt switch contacts could eat up significant current and convert it to heat for a few seconds when the switch is 'made'. That's the scorching you see inside the switch housings.
Thanks 7T1vette. After rebuilding everything in the doors the windows still took 6 sec up or down. Clean switches with a little dielectrical (awesome word) grease resulted in a huge improvement. After a good test drive and running the window up and down a few times with its new found strength it closes in 3 seconds!
Charlie
Power Window Motor replace:
