Hi,

I have a bit of a headlight puzzle and was hoping someone might be able to help or inspire me...

The passenger side headlight on my 1985 90 is not working on dipped beam. Works on main (full) beam. Sidelights and indicators are fine, drivers side is fine. Bulb is brand new.

Investigation so far:

Checked all connections especially earths and disconnected, cleaned up and reconnected all bullet connectors.
With the headlights on and using a multimeter i get 12 volts to the dipped beam switched feed when using the chassis as earth.
I get 12 volts to the switched feed when using the negative wire in the loom as earth.
I get 12 volts all the way to the bulb connector when using the earth spade at the bulb connector with no bulb connected.
Then i connect the bulb and all of my volts disappear and the bulb stays unlit!

It's this last bit which is confusing me, i get 12 volts on the meter at the bulb connector but when i plug the bulb in.. nothing. What could be stealing my volts?

Can anyone help or had a similar issue? I did a search before i typed this but nothing specific although i found a lot of useful stuff to help me work out the wiring in the wing.

Thanks very much,

Matt

If 12v is there without the bulb and not there when fitted it means that you have a high resistance in the dipped beam wire somewhere (the high resistance is dropping the voltage). As high works fine then the bulb earth is fine. Best advice would be to leave the bulb fitted with lights switched on then back track along the feed wire to see where the 12v re-appears.

I'll try that, thanks for the advice.

Matt