Headlights close slow and erratically when car on
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
Headlights close slow and erratically when car on
I just finished up the Daniel Stern headlight upgrade and noticed something very weird. If the car is not on the headlights will open and close normally. However as soon as the car is started they will open fine but when you shut the lights off then close about 1/4 way and close erratically. It's not a smooth motion they kind of close then wait then close a little more then wait etc. Does anyone have any idea what could be going on? It seems almost as if the gears are stripped but they close fine when the car isn't turned on.... 
Melting Slicks
Joined: Dec 2004
Posts: 3,284
Likes: 51
From: Jacksonville, FL
St. Jude Donor '08 thru '26
First, Thanks Dan for the other reply about the wiring & relay Q!
This is strange. If the bushings were bad the light buckets would studder and or not open or slam shut...that's what mine were doing before I replaced the bushings.
If the bushings are known to be okay, then it sounds to me that the motors are getting a smooth curent with the KOEO, but with the motor on it seems like the curent flow is spiking causing the DC motors to vary speeds? Do I understand your description of the symptoms correctly?
Do you hear anything from the gear cases? Have you put your ear close to the light assembly to listen to the sound of the motors when they are retracting?
Tom
This is strange. If the bushings were bad the light buckets would studder and or not open or slam shut...that's what mine were doing before I replaced the bushings.
If the bushings are known to be okay, then it sounds to me that the motors are getting a smooth curent with the KOEO, but with the motor on it seems like the curent flow is spiking causing the DC motors to vary speeds? Do I understand your description of the symptoms correctly?
Do you hear anything from the gear cases? Have you put your ear close to the light assembly to listen to the sound of the motors when they are retracting?
Tom
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
Ok, made some progress, if the high beams are turned on then the headlights will close fine with the car turned on. Also if I remove the high beam relay they will close fine. I switched relays and the low beam worked so the relays themselves are ok. There is either a bad ground or open circuit somewhere in the high beam circuit. Anyone know where I should look?
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
Actually now that I'm thinking about it more the high beam circuit should be ok, well it has to stay open for the lights to close. So the low beam circuit is probably at fault? Any ideas?
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
The scenario above was with both low/high beam relays receiving the ground from the driver side headlight. If I give one relay a ground from the driver and one from the passenger side the high beam indicator light comes on in the dash and won't shut off. I think solving this problem has something to do with the grounds on the driver and passenger side headlamps and possible grounding the foglight ground to chassis as they also affect this circuit. If someone understands these circuits and what is going on please let me know.
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Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,455
Likes: 2
From: East TN
Figured it out, the feed wires from the driver headlight go to the low/high relays, the ground from the driver headlight goes to the low relay and the ground from the passenger headlight goes to the high relay. Then the fog lights are grounded directly to the chassis instead of the high beam filament to keep the high beam indicator light from turning on when the fog lights are only turned on.