JF in MI

Before I dive into this; My C1 has the somewhat rare factory power windows and the motors are so weak (I'm guessing the magnetism is dead) they hardly raise the windows anymore. It looks difficult enough to remove the regulator on a manual crank system. Any tips on changing out the power motor?

dplotkin

Dead magnetism. Wish they sold it in a 12 OZ bottle instead of the 55 gallon drums.

Just kidding.

Almost always...when power windows get lazy its because the grease inside it has petrified and is munging up the works. You will need to remove the motors, disassemble, remove the 60+ year old grease and re lubricate. All of this is easily done at your work bench. Removing the motors is another matter, you will need your shop annual for that. However, if you can figure out how to remove the door panels, window motor removal will likely be self evident.

Dan

JF in MI

I appreciate the advise. I have been in there and lubricated the regulator mechanism. However, if I'm going to take out the motor for any reason I'm not going to fool with it, it's getting replaced with new once and for all so I don't have to do it again.

Rdelvalle

Op I also have original power windows. I bought the car September 2017 and have been restoring it since. Almost finished I only have the original Wonderbar radio to install and I am good for now. When I bough the car the windows had to be helped for them to move. Hardly any power. We did discovered that for some reason the problem was the windows were not grounded properly. When we ground the windows correctly they work and they go up and down with sufficient force. However, they do no have a lot of power.
I did a complete restoration of my hard top and the hardest part was the alignment of the windows with the vertical weather strip. I spent days trying to align it. When the window just touched the weather strip it will stop. It did not required a lot to stop it from working. So now they go up and down well but if they have any kind of resistance they stop.
I have been told that those old motors are very reliable but they lack power. My biggest fear is that I might have to replace those motors at some point. Consequently I have studied for many hours how to do it. Theoretically I think I know how to do it but it is not or the faint hearted.
I have a lot of experience taking out the door panels and working on the alignment of the windows as a result of the hard top. The biggest problem I had with the door panels was that the screw holes were damaged. I used JB weld and then when it was still soft I screw the screw and then took them out. When it fully cured then I screwed the screws and it worked very well.
There is a video on how to remove the window regulator, it is posted in other postings. Corvette C1 Window Regulator Installation and Removal. I do not know yet how to attach videos to postings. Here is what I think I will do.
Take out the window then you have to unfastened the window regulator , as shown on the video, so it is loose as if you are going to take it out. You do not take it out just let the end with the motor drop so that you can access the motor though the access door. Remove the motor and attach the new one. Then reattach the window regulator and the window.
I red in other postings that he window regulator has a wound spring that can be very hazardous. It can come unwound when you are dropping the regulator and can cause serious damage to you. This I red in another posting and it is the only thing that gives me apprehension in doing this job. Hopefully others that have done it can tell us what to avoid not to get hurt.
I dread the day I have to do it but it is very doable if you have patient and we figure out the coil spring issue. Just put your mind to it and be sure to study over and over again what you are going to do before you tackle the job. I am almost sure that you have to unbolt the regulator and let it drop at the motor end so then the motor can be removed and new one installed through the access hole, no need to remove the regulator. If the spring unwinds then maybe you do have to remove the regulator.

dplotkin

I do not believe "new" motors are available. I'm not familiar with C1 power window motors but it is likely they are the same or similar motor used in most period GM cars of which I own several. There might be new generic replacement motors or those designed to be added after the fact but the truth is that no motor is better than the ones you have. If you are going to the trouble to take the doors apart to remove the motors why not fix them and put them back? These motors were designed to last the contemplated life of the car, 10 years, and the grease inside is no longer grease. Certainly check the grounds as recommended too, but I'm a betting man and I'm betting the motors are having a tough time turning through that old grease. Once you re-lubricate the motors you will not need to deal with them again in your lifetime. The original motors are good quality and best of all, they fit!

Dan

JF in MI

Thanks. I'm pretty aware of the spring danger and I seem to remember that replacing a bolt (or something like that) in the regulator mount will stop the spring from unwinding all the way. I also was hoping what you said in that the motor can (has to) be replaced with the regulator still in the door loose.

JF in MI

The motors are big and round compared to contemporary styles and yes they seem to have the same mount pattern to those of similar years and most of the Corvette suppliers have replacements. I will certainly try what you recommend, because I have nothing to lose, but I still have my doubts. Thanks.

cbernhardt

Here is an article in PDF format that I found many years ago.
http://www.carols62.com/PowerWindows.pdf
(edit) I also noted that even with new after market power windows they were very sluggish with a hard top installed. If I want the windows to go up all the way I almost always need the engine to running so the voltage will be up around 14v.

dplotkin

That sounds like the motors in my 56 Cadillac, probably the same ones. In my experience the motors themselves do not often fail electrically, its usually a dirty or burned switch contacts often caused by holding the switch while waiting and waiting...for the window to travel. With thickened grease the motor armature struggles and up go the locked rotor amps, which burn the switch contacts.

Cars equipped with generators rather than alternators produce reduced or no current at idle depending on idle speed and the adjustment of the cutout on the regulator.
This reality is what makes may of us raise the idle while raising or lowering an electric convertible top. But proper power window motors should operate seamlessly and fast too. I'm pretty sure you do not want to use Lithium grease either, maybe someone reading this will weigh in, I'd use marine grease myself.

Dan

Rdelvalle

It will be nice if some one with experience with the spring will chime in. I did read about the bolt to stop the spring from unwinding but I think it was not clear how to do it. Given that this could be very very hazardous it will be nice if some one with experience would post photos and details on how to do it. Particularly the bolt concept. From what I remember the blot will prevents the spring from unwinding and thus prevents the necessity to remove the regulator to re-attach the spring. I am quite sure that you do not have to remove the regulator to change or fix the motor if the spring stays in place. But this is just what I think from studying the system, I have not done it.

Regarding the rebuilding of the motors I will most likely, if I had to remove them, will give it a great effort to restore the motors. One thing I have learned during the restoration is that it is much better to restore the original parts than buying re productions. This goes for emblems, chrome parts others.

Rdelvalle

Here is the link tot he posting that talks about almost losing a finger and also about the bolt trik.
https://www.corvetteforum.com/forums...dow-motor.html

Rdelvalle

Yet another posting. This one advices not to remove the 3 bolts holding the power window motors to the regulator. This can result in injury to your finger, The advice is to remove the regulator with the motor attached and then trouble shoot the motor without removing it from the regulator. I did not know it was possible to remove the regulator with the motor attached. It seems it can be done.

https://www.corvetteforum.com/forums...dow-motor.html

Rdelvalle

Ok another posting. This one states that the problem is when you separate the motor from the regulator. Power windows are spring loaded and when you separate the motor from the regulator the spring unwinds very fast and with a lot of force. It will cut anything on it way when unwinding uncontrollable. So the advice of the other posting to not separate the two is well taken. I guess I would take them out together and if I had to remove the motor from the regulator figure out a method to keep the spring wound. I am personally terrified of unwinding springs. I had close calls while cleaning guns, a lot of potential energy suddenly released as kinetic energy.
https://www.corvetteforum.com/forums...r-removal.html

Rdelvalle

Me again. Mid-Atlantic Corvette Restoration, C1 power windows motor restoration services. Definitely this will be the route I take when I have to do it.

http://www.midatlanticcorvetterestor...ration-service

buns

You need to remove the motor and regulator as a unit. Take the unit to the bench and with a 12 volt power supply, run the motor until the hole in the regulator lines up with one of the regulator mounting nuts. Insert a 1/4"-20 bolt.

New motors are available from the usual vendors, $80.00 each.

Rdelvalle

Buns thank you so much. So you can remove the regulator and the motor together? they fit through the bulwark opening (C1s)? When you remove the regulator holding bolts the spring does not unwind?
Have you used the new motors? Fit well have enough power?

Rdelvalle

One more question. When you insert the 1/4"-20 bolt can you then remove the motor and the spring will not unwind?

buns

^ That is correct.

Frankie the Fink

There are some tricks to R&Ring the regulators in and out of the later C1 doors....this is a manual regulator manipulated by a very famous Corvette restorer:


I don't know how that relates to power window regulators but 'm betting there are some tips worth noting...