Headlight motor

BLIMP

BLIMP

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I've been pouring through the forum with the Search feature, trying to find the answer to my question with no luck. I'm pretty sure I've read the answer before but I can't remember what it was.

When turning the headlights on in the 73 Imperial, I have to manually roll the doors up. But it will close properly when the light switch is turned off.

I'm guessing the problem is the motor itself?
 
BLIMP said:
I've been pouring through the forum with the Search feature, trying to find the answer to my question with no luck. I'm pretty sure I've read the answer before but I can't remember what it was.

When turning the headlights on in the 73 Imperial, I have to manually roll the doors up. But it will close properly when the light switch is turned off.

I'm guessing the problem is the motor itself?
Click to expand...

Not necessarily the motor. You have to troubleshoot the wiring to the motor and the switch first. If you don't have the FSM you might want to get a set. You can get them on EBay or bishko.com relatively cheap. The FSM have complete wiring diagrams and other troubleshooting help. I would also recommend a parts book if you plan on keeping the car.
 
I suggest you to check the limiter switch.

Power 008.jpg
 
Opening up the motor can be very tricky AMHIK. If the motor is working one way and not the other it could be a relay problem. There are several threads here on troubleshooting this problem. Try searching for Headlight Door Relay. Good luck and always grab spare motors when you can I always say
 
When (if) you take the headlight motor out, here´s a few tips:
1 A heat gun helps to get the metallic bar (yes, only one going through the motor) detached from the headlight covers and
2 Never bench test the motor without load, per the BSM it may damage the actuator cam.
3 when detaching the headlight motor, the covers should be positioned in the middle of their movement.
 
You can test the relay by disconnecting the plug from the motor, turn on the light switch and ignition switch, now take a test light and attach it to one of the disconnected terminals. One or the other of the terminals should light the test light. Now turn off the headlight switch but leave the ignition on. The other terminal should now light up the test light. If you get power to both leads using this method, you relay is probably still good. If you decide the service the limit switch, have the motor at the center of travel as noted above. I suggest that you do not remove the end cap from the motor as the brush holder assembly is made of brittle material and easily broken and there is no replacement available. The last one I had rebuilt was done by: (e-mail)
stephan.fournier@videotron.ca if you are looking for a restoration quality job.

Dave
 
If you want to do a very simple test of the motor itself. Wind the doors shut. There's only two wires that go the motor. Unplug the connector, apply battery voltage to one side and ground to the other. They should open. If nothing happens reverse them and they should open. Once open, reverse the test leads and they should close. That simple. At least this simple test will verify that the motor and limit switches are working. Don't leave the power less on to long. Just a couple of seconds is all it takes.

I remember I had the same problem on Old Red. I traced it to one of the bulk head connectors. It was dirty. It's to the right of the brake booster on the fire wall, below the hinge.... there are two if I recall. I think it was the smaller one, of course it was the more difficult one to get to. The FSM will tell you.
Take it apart, look for any corrosion or signs of over heating. I cleaned the terminals with crc electrical contact cleaner, then packed it with dielectric grease... and Bingo.
Even if that's not it, at least you did a great piece of P.M. because EVERYTHING going to the engine compartment runs through those Bulkhead connectors.
 
Thanks to you all for the great info, I will look into it more when I get home from work.
 
Ok I ran a hot wire to the motor...it will only operate to close the doors. With direct current it will not open the doors. I'm going to look through my FSM now and see if there's any info on it.
 
BLIMP said:
Ok I ran a hot wire to the motor...it will only operate to close the doors. With direct current it will not open the doors. I'm going to look through my FSM now and see if there's any info on it.
Click to expand...

Your switch plate is bad. The opening cycle of the headlight system produces a lot more load on the motor that the closing cycle, so it is usually the points for the opening cycle that carbon up or burn out.

Dave
 
Ok well next day I'm free I'll pull the motor and check the switch plate. I have a couple core motors that are seized but should be good for parts. Thanks again fellas.
 
Well 1st off I'm guessing there are more manuals for 1973 because I couldn't find squat in these two in regards to the headlight motor assembly lol.
20190121_125314.jpg

But thanks again for all the leads and suggestions. I read all your posts more than once and kinda had an idea what was going on, so this afternoon I removed the motor and took the switch plate off. Even though you guys told me more than once to put the motor in the middle position, I neglected to. But I quickly learned why, the cam bent one of the switches upon dissasembly. Actually it was the same switch that I'm guessing was the problem, as it was dirty and discolored. So I scuffed and polished it up a bit, fixed the exposed plug wiring, and buttoned it back up. Tomorrow I'll reinstall it and post the results. Here's a few pictures and thanks again!
20190121_141706.jpg
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I copied the following from a discussion several years ago.

Remember to turn the manual knob back to the alignment marks after testing, this puts the motor in the middle of it's range & you lift the doors to the halfway open position to install it. At least for a 70 anyway, I'd think the other years would be similar.

To clarify that a bit.....look at where the square shaft goes thru the gear housing to each door, There a little pip mark on the outer section that doesn't move & a pip on the center that turns. You just turn the manual knob at the bottom & line the 2 marks up with each other.

Bolt it up, slide the square drive thru, lift the doors ( you can do 1 at a time ) until the square drive falls into the slot in the doors ( doors should be about the half way open point ) Don't forget the spring steel retainers that slide over the square drive & hold them to the doors. Once both are hooked up, connect the wires , get in & turn the key on...doors should close if everything is working.

Headlights will come on without the key on but the doors won't open until the key is on.
 
Thank you Fury440...actually I did notice those pips, makes it easy to locate!
Screenshot_20190121-195105.png
 
BLIMP said:
Well 1st off I'm guessing there are more manuals for 1973 because I couldn't find squat in these two in regards to the headlight motor assembly lol.View attachment 249166
But thanks again for all the leads and suggestions. I read all your posts more than once and kinda had an idea what was going on, so this afternoon I removed the motor and took the switch plate off. Even though you guys told me more than once to put the motor in the middle position, I neglected to. But I quickly learned why, the cam bent one of the switches upon dissasembly. Actually it was the same switch that I'm guessing was the problem, as it was dirty and discolored. So I scuffed and polished it up a bit, fixed the exposed plug wiring, and buttoned it back up. Tomorrow I'll reinstall it and post the results. Here's a few pictures and thanks again!View attachment 249167 View attachment 249168 View attachment 249169 View attachment 249170 View attachment 249171 View attachment 249176
Click to expand...

@BLIM there´s a full chapter about the concealed headlights on the body service manual.
 
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