C34 S1 Headlight Dramas

[woggin]

Hey all,

Am currently driving my mates s1 c34, which is having some headlight dramas, left lo-beam works, and only the right hi-beam works, so collectively i can drive around with a lo and hi beam, but obviously, thats not ideal. He has checked the fuses, relays and globes, all good, i got him to do some probing with a multimeter, but ill start from scratch again once i grab a multimeter off him. (not that i dont trust him, but he hates electrics!)

Has anyone heard of a similar issue?

Does anyone have wiring diagram for the headlights? (ive searched and cant find much)

any suggestions would be great

cheers

soti

[Stick180]

Check to see if there is power at the lights, if there is, then try another headlight stalk.

[woggin]

there is power at the lights, but its all over the place, theres power when there shouldnt be, but no illumination, and there isnt power when there should be, is it a switched ground trigger?

i can get the bulb to illuminate at the weirdest times, then at other times, not at all...

[woggin]

there is no ground wire connected to ground, theres a positive 12v, but no ground, then if u switch to high beam, another wire is activated and if u connect that to the other positive on the bulb, u get a light, 2 positives and no ground, you get a light,

but the other headlight,

theres always 2 active 12v lines with the low beams, then once you switch to high beams, one drops off and you have just the 1 positive, but you dont get low and high beam active when its set to low beam even though theres 2 12v lines active,

its like when theres a defect with the system, it drops a low beam off one, and a high beam off the other so u have 2 working lights.

is there a control module for the s1 headlights, or just the stalk and a few relays? does anyone know if the s2 headlight stalk is the same as the s1 stalk?

[zoomzoom]

From memory the headlights are ground switched. The H4 connector on the harness should have a 12v supply, then either the hi or low beam is earthed to complete the circuit. Have you tested the voltage, and resistance to earth of each pin in each state (ie off, lo, hi)?

The 12v supply is probably the right pin if you look at the female connector front on.

Also I seem to remember seeing some voltage on other pins, but it dropped when a small load was applied. So you may need to test the voltages between the pins of the bulb when it is plugged in. There may be voltage but not enough to get the bulb to incandesce.