new to the board ,thanks for having me,im going through the headlight motors,im pretty good with electrics,i have a caddy allante that ive fixed most parts that have puked out,my question is about testing the motor once apart,are thier ohm readings for the windings,also whats the points looking thing in there ,and is there a test for that,any help would be great ,thanks
67 charger headlight motors
- Thread starter rags712
- Start date
Think that what you are referring to is a circuit breaker of sorts that protects the motor winding(s) from excessive current draw should they be stalled mechanically. protecting the windings. You should see continuity across it. Motor case is ground and there is a motor winding for each direction. The 3 relays behind glove box control motor activation and direction. The two limit switches at rotating headlight buckets turn off motors when in fully open or closed position. 12 volts applied from case ground to either wire should make motor work. On resistance values, I checked a good motor, it shows 3.2 ohms on one winding and 2.8 ohms on the other. Different wire gauges is used on the windings, as there is a speed is difference for open and close, thus the resistance difference. There is a guy 'Thopher, the headlight motor man" that does motor repairs for Chargers. http://headlightmotorman.com/. Hope this helps.
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thanks it clears up some things,ive talker to him and i think hes jammed up with work from what i hear,ive done alot of electrics on my cars and figured this cant be that hard,it wiers the brushes look ok ,the windings dont look burnt nothing is binding,i apply 12 volts and not a thing happens,i did find what looks like a metal pad for the circuit breaker ,it was bouncing around inside ,i thought my allante was a pain in the *** ,this things driving me nuts
If you have it partially apart and you can measure resistance from the case ground to the windings, and they appear to be at the approximate value of the resistances mentioned in the previous post, windings are probably OK. If the motor base is together, with the planetary drive removed, you need to use the dish shaped nylon piece, which is the first item of the planetary drive outward from the phenolic plate with the brushes mount, placed over the shaft to properly support the armature shaft and center up the commutator between the two spring loaded brushes. Also have the end of the housing where the wires enter vertical oriented so gravity will keep the base of the armature in the lower bearing of the housing. Otherwise, the armature can't freely spin and can bind up. This below video link video someone posted does not have much useful info on the motors, but does demonstrate the binding up I describe if commutator is not kept properly centered between the spring loaded brushes. You mentioned a pad broken off inside, think it's part of the thermal circuit breaker ? That must have continuity for motor to work in either direction as it's in series with the ground connection, or motor case.
The motor(s) do require a stiff 12 volt source as either of the windings will draw a significant amount of current from your voltage source., about 4-5 amps. What are you using as a power source ? Battery charger ?
The motor(s) do require a stiff 12 volt source as either of the windings will draw a significant amount of current from your voltage source., about 4-5 amps. What are you using as a power source ? Battery charger ?
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mventura83
Member
Hey, so I’m in the process of troubleshooting my rotating headlights. I have found that I am getting power to the motors when the head light switch is pulled with the upper limit switches released and also getting power on the other terminal when the light switch is off with the lower limit switch is released, but motors will not run. I put power strait to motors and still won’t run. I also have 2 spare motors that came with the car when I bought it and put power to them and they won’t spin either. I did find out ringing continuity from the motors plug the ground has continuity to both power terminals on all 4 motors. Is the normal or are all of them shorted.
The headlight motors have two windings, one is for opening direction the other is for closing direction. The outer case is ground, or common, to both windings. If the motor does not move in either direction with voltage applied as you indicate, it's possible that either the windings could be open or shorted, or shaft could be seized up. Don't try spinning the shaft by hand as you can strip the internal planetery drive gears which are plastic !! There is a protective thermal circuit breaker internal to the motor to protect the windings if motor is stalled. If I recall correctly, that circuit protection is in the common or ground connection within the motor offering protection for both motor windings. This being a DC motor, there are brushes and a commutator that could also be at fault. These motors do draw quite a bit of current even when operating properly. Strange that out of the 4 motors you report that all act the same... Do resistance measurements across all the motors from ground to each winding. Does that resistance measurement seem consistent motor to motor ?
I have found that a common problem with these motors is the seal / bearing where the shaft exits the front housing. In that front housing, there is an embedded ring in the front casting surrounding the shaft that is made of some sort of hard plastic. It's meant to be a snug fit unto the shaft to seal out moisture. It will shrink with age seizing the shaft. If you get the housing separated and motor apart, it will be apparent if that's your problem. I have used some fine emery cloth to clean up the OD of the shaft and ID of that front housing plastic bearing/seal with success. You want the shaft to move freely without resistance. It's possible your problem is mechanical not electrical.
I have found that a common problem with these motors is the seal / bearing where the shaft exits the front housing. In that front housing, there is an embedded ring in the front casting surrounding the shaft that is made of some sort of hard plastic. It's meant to be a snug fit unto the shaft to seal out moisture. It will shrink with age seizing the shaft. If you get the housing separated and motor apart, it will be apparent if that's your problem. I have used some fine emery cloth to clean up the OD of the shaft and ID of that front housing plastic bearing/seal with success. You want the shaft to move freely without resistance. It's possible your problem is mechanical not electrical.
mventura83
Member
I measured the resistance from one positive terminal to the ground terminal and they all are reading between .8 ohms and 1.5 ohms. I had taken one motor apart and it runs with the gear drive part removed so I cleaned up the output drive shaft and bore and it spins freely by hand. Once I install the inner cup that splines the output shaft and the one half of the outer case together it doesn’t spin. I’m wondering if I’m putting it together wrong. I’m trying to understand how this manual gear setup works. Thanks in advance.
I second Topher as the expert. I met him a couple months ago as he was in town and I handed off my 70 charger wiper motor and headlight motor - definitely a cool dude. I got them back a few weeks ago when he was back in town - all tested and looking like they came from the factory. Well worth the dollars to be worry free.
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