Only one headlight goes down... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DamnedButDetermined · 08-21-2012, 12:13 PM

Here is what is going on...
Light switch off and retract button in the down position (right light goes down left light stays up)
Light switch on and retract button in the down position (right light goes up left light stays up)
Light switch off and retract button in the up position (right light goes up left light stays up)
Light switch off and retract button in the down position...Then manually try to lower the light with the twist knob on the motor and the light will slowly go down
Light switch off and retract button in the up position...Then manually try to lower the light with the twist knob on the motor and the light will slowly go down until maybe 1 1/2 turns and then the motor fights you and tries to stay up
Light switch off and retract button in the up position...Then manually try to lower the light with the twist knob on the motor BUT turning the knob the opposite direction than the arrow and the light will slowly go down until maybe 3 1/2 turns and then the motor takes over and brings the light down and back up in one fluid motion.

I pulled the FSM and looked at the wiring and I thought I had a good plan in order. There are four relays in the headlight electrical system and two of them are used for the up and down of the headlight motors. Since one of the lights would go down when they were supposed to, I figured the one that controlled the faulty headlight was broken.

Based on the wiring diagram it looks like relay #1 controls the left headlight motor and relay #3 controls the right headlight motor. So I switched the #1 and #3 relays to see if the other headlight would stay up and the originally broken one would go down, but nothing changed. The right headlight would still go down and the left headlight was stuck up. So I decided to swap the #2 and #3 relays to see if anything different would happen but everything stayed the same.

Relay #4 is a different kind of relay and I couldn't find another one that looked like it to try and swap it with.

Does anyone think it is the relays or would it be something else?
I wouldn't think it would be the motor because it operates when you mess with the manual turn knob. Unless it is the detecting switch inside the motor...Can that be replaced or would the whole motor have to be replaced?
I wouldn't think it would be the combination switch because the right headlight works normally.

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08-21-2012, 12:13 PM	#1
DamnedButDetermined Zilvia Addict Join Date: Oct 2002 Location: Jax, Fl Age: 39 Posts: 637 Trader Rating: (1) Feedback Score: 1 reviews	Only one headlight goes down... Here is what is going on... Light switch off and retract button in the down position (right light goes down left light stays up) Light switch on and retract button in the down position (right light goes up left light stays up) Light switch off and retract button in the up position (right light goes up left light stays up) Light switch off and retract button in the down position...Then manually try to lower the light with the twist knob on the motor and the light will slowly go down Light switch off and retract button in the up position...Then manually try to lower the light with the twist knob on the motor and the light will slowly go down until maybe 1 1/2 turns and then the motor fights you and tries to stay up Light switch off and retract button in the up position...Then manually try to lower the light with the twist knob on the motor BUT turning the knob the opposite direction than the arrow and the light will slowly go down until maybe 3 1/2 turns and then the motor takes over and brings the light down and back up in one fluid motion. I pulled the FSM and looked at the wiring and I thought I had a good plan in order. There are four relays in the headlight electrical system and two of them are used for the up and down of the headlight motors. Since one of the lights would go down when they were supposed to, I figured the one that controlled the faulty headlight was broken. Based on the wiring diagram it looks like relay #1 controls the left headlight motor and relay #3 controls the right headlight motor. So I switched the #1 and #3 relays to see if the other headlight would stay up and the originally broken one would go down, but nothing changed. The right headlight would still go down and the left headlight was stuck up. So I decided to swap the #2 and #3 relays to see if anything different would happen but everything stayed the same. Relay #4 is a different kind of relay and I couldn't find another one that looked like it to try and swap it with. Does anyone think it is the relays or would it be something else? I wouldn't think it would be the motor because it operates when you mess with the manual turn knob. Unless it is the detecting switch inside the motor...Can that be replaced or would the whole motor have to be replaced? I wouldn't think it would be the combination switch because the right headlight works normally.