'85 Headlight Motors Going Out
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 2,384
Likes: 124
From: Reno/Sparks Nevada
'85 Headlight Motors Going Out
Seems after 20 years the headlight motors are finally giving out. The left stops rotating to the down position occasionally. The right side is now non operational. There is no continuity between any of the wires going to the motor. There is the proper voltage and polarity at the harness plug going to the motor. The left headlight would rotate down after pushing on it a few times to get the torque switch inside to make contact. The right side won't go up or down. I tried manually torqueing the switch by rotating the **** as far as it will go but I can't get any continuity through the motor. I've had the motors apart years ago for a cleaning since it happened before. They worked flawlessly afterward until now. My question is: Should I replace them with the early style motor or go with the later style? I've never had a gear problem with mine but have heard that is the problem with the later motors. I think that 20 years is pretty good for the early style motor. I might try taking them apart one more time for a good cleaning to see if that will work. My relays, all three, are operating correctly. The voltages at the motor connectors is fine. Just like everything, time takes it's toll. Any comments appreciated.
Art
Art
Racer
Joined: Jan 2004
Posts: 380
Likes: 0
From: New Hampshire There's nothing like a 'Vette
I had a similar problem with my '85. The external relays/wiring were all ok, but the limit switches inside the motors were shot. I found a post here describing how to convert the 3 wire motors to 2 wire operation, eliminating the internal switches and the external relays replacing them with a headlight control module from a (salvage yard) Firebird. It sounded like the thing to do at the time, it was certainly cheap enough and it does work fine, but if I had it to do all over again I'd just buy rebuilt 3 wire motors. The price of converting to the late type motors seems excessive to me, but.......I'm a cheap ba$tard 
.
.
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 2,384
Likes: 124
From: Reno/Sparks Nevada
Rebuilts are $150 each for the early motors. Late motors are $150 each but you have to buy the extras for another $150 or so to make them work. I've never had any problems with my motors until the switches inside started going recently. I hear a lot about bushings and stripped gears in the later ones. I'm a cheap guy too and since I do all my own work on the car myself that makes me an even cheaper guy. Thanks for the reply. Rebuilding my old ones seems more reliable right now, and cheaper.
Art
Art
Thread Starter
Melting Slicks
Joined: Jul 2003
Posts: 2,384
Likes: 124
From: Reno/Sparks Nevada
I dismantled the motor and found out the brushes to the armature are worn down to almost nothing. I thought I could clean one of the brushes and it fell off of the brush spring arm. That's why I didn't have any continuity in the motor, it was open. So my choice is to buy another used one hoping it is in better condition or take it to a electric motor repair shop and see if they have a brush arm they can attach to the housing contact module or attach a brush to the existing arm. What's interesting is there is a brush and torque switch module that is screwed to the motor housing. It's a separate part which all the wiring is connected to. It's replaceable but who knows where to get them for the early motors? I know it's hard to picture but this separate part, if new, would probably fix the motor right up. Anyway, I've got an email in to someone parting out an early C4, maybe they'll part with a good used motor. More to follow.
Art
Art
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
If you're looking for motor brushes, call Tool Repair Service, Inc. at 502-635-6888 at 1200 Goss Ave., Louisville, KY, 40217.
I bought a pair of Bosch electric motor brushes for the headlights in my 92 Coupe last summer. The parts number is 3604321509.
I had to use a piece of emery cloth to sand them down to fit, but my lights are working great now.
I bought a pair of Bosch electric motor brushes for the headlights in my 92 Coupe last summer. The parts number is 3604321509.
I had to use a piece of emery cloth to sand them down to fit, but my lights are working great now.
