The passenger side '84 SE headlight motor 'twitches' when it's off, eventually draining the battery. It's not the rubber seal at the top; that's in place. It appears to function normally otherwise. Is it likely an electrical/mechanical issue with the motor assembly or could it be a relay or something else?
It could be one of the headlight relays. Easy way to find out is swap the two relays and see if the twitch moves to the other headlight. If it doesn't, the most likely cause is your limit switch. Take the cover off and see if both of your brushes are still on the switch. If one is gone, there are a few threads on here that describe how to attach a new brush. You can't glue it because glue won't conduct electricity well enough for the limit switch to function properly. Other option is to find a used limit switch, but I think they're becoming pretty rare.
+1 on the limit switch, but also the most basic problem with these motors is there are rubber bumper parts that are supposed to soften the stop when the headlights reach full up or down. These things disintegrate, the plastic gears get worn, and the headlights don't quite shut off, as you describe.
My solution is to install a switch in the white wire from the headlight switch to make lowering the headlights an option. Because the white wire provides the signal for the headlights to close - no signal, no power, no close, no twitch. I've been using a push-pull switch installed in place of the dimmer switch (which I just push back out of the way left in full bright setting), but a momentary switch (pushbutton) might be even better. As a practical matter I just turn the switch on when I want the headlights to close. Then I turn it off again to avoid the twitching problem.
Thanks! I switched the relays to no avail. I took the whole thing apart & couldn't see anything that didn't look ok, so I'm going to try another motor.
I have a switch in the console that I used for after-market driving lights. I gave up on those after two sets disintegrated before the first gear failure! Now when the gears fail, I unplug the power & poke the switched power line into the connector. That bides me some time before I have to replace the gear again.
[This message has been edited by David Hambleton (edited 10-30-2013).]
I finally got tired of the twitch after it came back following my rebuild due to a bad limit switch. I bought the gen 2 motors and harness and am soooo happy I did. The task looked a bit daunting at first, but once I got it started it was really pretty easy and managed to get it all done in a couple of hours not counting the time I put into replacing the disintegrated bump stops before putting the motors in. Well worth the time, effort and money. I think it was about $175 total for motors, harness and bump stops.
If you're in the market for a Rodney aluminium gear rebuild kit, I've got one for sale.
If you've recently rebuilt the motor, some of the rubber bump stops being provided tend to compress more and allow the points to engage again. This causes the ticking. If the motor hasn't been rebuilt, then the old bump stops have deteriorated. That rubber seal you mentioned is a major cause of ticking if it's between the top of the case and the knob. Another cause of the ticking problem is that one of the brushes has broken off and the motor can't generate enough speed and torque to fully open the points and shut the motor down. It can eventually burn out the motor. I would recommend in the meantime that you disconnect the single blue wire except to raise or lower the headlight, then disconnect it again.
If you find no obvious cause of the ticking and you've recently rebuilt the motors using the rubber bump stops, I have bump stops that are of a little higher density and have been very effective in resolving this problem. They're $5 per set or $8 for 2 motors. If interested, you can email me from the link at the top of my post. Don't PM me because my computer is down and I only have occasional use of a laptop, but I can check emails on my phone.
