Single to Twin headlight - wiring

**RedMk2Gti** · 08-07-2008, 03:07 PM

I am always in favour of twin headlight and bought a twin headlight Mk1 grill from a forum member a while ago. It comes with the high beam light so I need to wire the high beam from the main headlight to it.
Sound simple, I connected the new high beam in the grill to high beam wire in the main headlight, and then earth the ground wire.

But i found both the high beam and low beam wire in the main headlight has power when I switch on low beam, when I switch on high beam, the high beam wire cut power. So end up, the new high beam goes ON when I turn on low beam, and goes OFF when I turn on high beam

Do I need to add some relay to make it work ?

**abreut** · 08-07-2008, 03:18 PM

I'm pretty sure you have wired it the wrong way around. Sounds like you wired up to the low beam. Can't remember which wire colour is which but whichever one has 12v "ONLY" when high beam is on is the one you want. If you have a test lamp or multimeter just probe the pins on the main headlight plug, get someone to flick high beam on and off.

Also, when you flick high beam on and you haven't let go off the headlight lever (its still pulled towards you), you momentarily have both high and low beam on. That might be why you mixed them.

**RedMk2Gti** · 08-07-2008, 03:26 PM

Originally Posted by Grunmk1

I'm pretty sure you have wired it the wrong way around.

That's what I think as well

will keep trying tonight. Thanks.

**mollins** · 08-07-2008, 03:29 PM

as above, sounds like something is wired badly..

to install the twin headlights you might want to put in another relay .. this would use the high beam voltage to switch power directly from the battery to your grill lights so you dont blow your high beam fuse .. depends on what wattage the bulbs in your grill is.

you can buy a wiring kit from supercheap for driving lights for about 30 bucks i think.. should do the job..

good luck

mike

**h100vw** · 08-07-2008, 03:49 PM

White is the high beam and yellow is the low beam.

Gavin

**abreut** · 08-07-2008, 03:53 PM

Yeah I agree, the first thing I always do to a mk1 is put a couple of relays near the battery to switch power straight from the battery to the lights.

Even with puny 55W bulbs you suddenly have all this light. The standard headlight wiring is pretty out there, maybe they had the graduate engineer design that part...