Im trying to wire up my driving lights with my main beam, following alcazar's 'how to' guide.

Problem is identifying which wire from the light plug/socket is controlling my main beam ...as two of the 3 wires when dipped are reading +12v ...& only one when main beam is selected?

If i connect my relay to this, i can switch to main beam, but can't cancel them?

Anybody got any ideas?

 

Yep always confuses. For sume unfathomable reason the lights are switched negative rather than switched positive (as used by the other 99.9% of car makers. There's a constant 12V on one side and the other side (or other two sides for a twin filament, three terminal H4 bulb) is put to earth by the switch to turn the lights on.

When the light is off (and the plug attached to the bulb) you'll find 12V on both sides (or all three for an H4). When the light is on you should be able to measure 12V on one side and earth on the other of the filament on and 12V on the third for the filament turned off. With the plug disconnected from the bulb (may need to disconnect both left and right bulbs) you should be able to measure 12V on one side and 0V (but not earth) on the other two terminals.

Can't comment on how you wire this to the aux lights as I don't have access to Alcazar's guide. Can you post a link?

Oh and what age and model car? I may have the wire colours.

 

Cheers Chelspeed,

Whilst searching for alcazar's post i found this...

https://www.scoobynet.com/lighting-o...potlights.html

kind of makes sense now ...& instead of running my relay from -ve ill use the other light plug terminal, ill let you know how i get on

Cheers again,

D.

 

cracked it ...cheers Chelspeed!