How does the headlight motor work?
Thread Starter
Drifting
Joined: Feb 2010
Posts: 1,734
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From: Richmond Texas
How does the headlight motor work?
More specifically, how does it change direction? Do the two wires switch polarity? Or is it powered to either wire to switch direction and then grounded through the case?
Melting Slicks
Joined: Jul 2005
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From: Strongsville, OH
2016 C2 of the Year Finalist
Each wire of the two to the motor carry current directed by the dash switch. One powers when the switch is up and the other when its pushed down. The case supplies the ground. 
Thread Starter
Drifting
Joined: Feb 2010
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From: Richmond Texas
Thanks. I had one that quit working. I took it off and hooked it up to a battery direct and got it to work in one direction, but it won't work in the other direction. The brushes looked good, I only seen one set of contact points and it looked good. Maybe the one wire is broken on the inside....
The gears and all looked good and turned freely.
The gears and all looked good and turned freely.
Team Owner
Joined: Aug 2007
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Army
All of the above is correct, if the gears are good and grease not congealed the motor should turn in both directions. However, these motors are very weak by design and barely adequate for the job.....there is a pre-load adjustment on them (external screw and lock nut) that may be set so the motor works one way but can't reverse.
Loosen the nut and turn the screw in/out while running the motor one way until it just drags then back off a nit...do the same in the other direction. when you find the best balance between the two directions tighten the lock nut.
Loosen the nut and turn the screw in/out while running the motor one way until it just drags then back off a nit...do the same in the other direction. when you find the best balance between the two directions tighten the lock nut.
Thread Starter
Drifting
Joined: Feb 2010
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From: Richmond Texas
for some reason it won't spin in the second direction. On the car it wouldn't go either direction. It's the original motor. When I took it apart to inspect it, it did have that nice toasty smell to it. I am hauling it to work with me, I have a lot more electrical test equipment there. I will see if i can screw it up worse..... Uh I mean fix it up.
Team Owner
Joined: Aug 2007
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Army
Well - if the motor will go in either direction with the manual thumbwheel easily then the mechanicals/gears are good....meaning that funky smell might be some burnt windings and maybe that's the issue (bad news)...
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Thread Starter
Drifting
Joined: Feb 2010
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From: Richmond Texas
It's not judged by any means... still has the original drivetrain, but I have added PS and vintage air and knock offs.
I ordered the headlight kit from Summit. Putting my other stuff in the box on the shelf with all the other original parts to my car. I could probably sell all that stuff for some good coin.I have the original steel wheels, hub caps, some NOS exhaust, side covers, heater box... Hmmmm Wonder what else is up there. I am going to have to look tonight
I ordered the headlight kit from Summit. Putting my other stuff in the box on the shelf with all the other original parts to my car. I could probably sell all that stuff for some good coin.I have the original steel wheels, hub caps, some NOS exhaust, side covers, heater box... Hmmmm Wonder what else is up there. I am going to have to look tonight
Team Owner
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Army
There may be somebody around with the talent to fix that wiring; certainly not me. A used original or rebuilt motor from 63-67 would work. I run the Detroit Speed kit though and that is certainly an option..
Racer
Joined: Aug 2004
Posts: 313
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From: Richmond Va.
There are two field windings in these headlight motors. They are wound in opposite directions. This usually happens when a mounting screw that is too long is installed and shorts one or both windings to ground. I have repaired some of these but its not and easy fix. Did you put any indexing marks on the back cover before removing it? Is the rear bearing still in the rear cover?
Thread Starter
Drifting
Joined: Feb 2010
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From: Richmond Texas
I marked it before I took it apart and the rear bearing is still in the cover.
There is a electrical shop down the road that rebuilds components. I am going to stop by and see if they can do anything with it.
I bought the car in 84 (ish) and that motor has been in there since before then, The screw wasn't to long for the ground wire and there are no marks where it hit.
Ever since I noticed that has always been the slower one of the two, especially on closing.
There is a electrical shop down the road that rebuilds components. I am going to stop by and see if they can do anything with it.
I bought the car in 84 (ish) and that motor has been in there since before then, The screw wasn't to long for the ground wire and there are no marks where it hit.
Ever since I noticed that has always been the slower one of the two, especially on closing.
Last edited by SledgeHammer 2.0; Aug 21, 2015 at 04:07 PM.
Racer
Joined: Aug 2004
Posts: 313
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From: Richmond Va.
Hopefully it's the outer winding. Sometimes you can start unwrapping the shorted winding and if you get to the short in 3 or 4 wraps, just cut off the bad part and re-solder to the plug. If a lot of winding needs to be cut out you may have to measure the wire that was unwrapped and replace it with some insulated wire on the same size and type that was originally used. From the picture it looks like the short happened near the plug. There used to be a plastic tab that the burnt wire was loped around before it went to the plug. That tab is burnt off but no be deal. The two windings that are wrapped in opposite directions are tied together on the other side of the motor were they are connected to a white insulated wire that goes to the thermal overload breaker. You can check the winding with and OHM meter to see if they are shorted to ground or if it is still a circuit through both windings at the plug. Good luck and let me know it I can help.
Last edited by packrat; Aug 22, 2015 at 09:01 AM. Reason: spelling
Thread Starter
Drifting
Joined: Feb 2010
Posts: 1,734
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From: Richmond Texas
Well, I unwound part of the winding and found the broken piece less than a turn in. I attached it back to the post with just a crimp and put the motor back together and It Works.
Forward and backwards spins away like it did. My victory was short lived, I put it back on the car and it doesn't have enough power to move the door. You can hear it trying, but it just doesn't have the ummph. Bummer..... It's probably got to much resistance in that winding, probably the reason it shorted out before. I will tag it and put it in a box with the other one, on the Corvette Shelf.
Forward and backwards spins away like it did. My victory was short lived, I put it back on the car and it doesn't have enough power to move the door. You can hear it trying, but it just doesn't have the ummph. Bummer..... It's probably got to much resistance in that winding, probably the reason it shorted out before. I will tag it and put it in a box with the other one, on the Corvette Shelf.
Team Owner
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Army
Safety Car
Joined: Aug 2011
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Go with the real deal
Why are you guys always trying to change perfection. There are thousands of these cars with the original motors working as they should. If you do not wish to try and rebuild your original, send it off and get it rebuilt. Buying these generic over the counter motors where you have to cut up all your original wiring and adding supports for the new motor takes away from the value of the car. And with the hood open, they look like crap. Get that original motor rebuilt and it will last longer then you and be much cheaper.
Team Owner
Joined: Aug 2007
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Army
Why are you guys always trying to change perfection. There are thousands of these cars with the original motors working as they should. If you do not wish to try and rebuild your original, send it off and get it rebuilt. Buying these generic over the counter motors where you have to cut up all your original wiring and adding supports for the new motor takes away from the value of the car. And with the hood open, they look like crap. Get that original motor rebuilt and it will last longer then you and be much cheaper.
As far as perfection -- tell that to the guy on a moonless night alongside the road frantically cranking on that manual thumbwheel to get his original lights up and working
I did rebuild my original '63 motors and they are on the shelf for some future owner to re-install and fiddle with...
Thread Starter
Drifting
Joined: Feb 2010
Posts: 1,734
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From: Richmond Texas
The only thing you can really see is the wire that runs alongside the original harness. Just installed mine, no cutting of wires. Did drill one hole for the ground wire in the crossbar. While they do come up faster than the old one(s) they aren't as fast as some make them out to be.