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Headlight upgrade wiring diagram

Posted: Sat Feb 11, 2012 1:34 am
by georryan
Looking to finally do the wiring and headlight upgrade on my 91 TLegacy. I looked for the wiring diagram but the links seemed to be broken.

Will this wiring diagram work?

http://forums.vwvortex.com/showthread.p ... conversion

Re: Headlight upgrade wiring diagram

Posted: Sat Feb 11, 2012 3:12 am
by kimokalihi
I've always wondered if upgrading the wiring to the headlights would make them brighter. The wiring looks like it goes into a harness and disappears so I've been discouraged from trying.

Re: Headlight upgrade wiring diagram

Posted: Sat Feb 11, 2012 3:42 am
by PhyrraM
That diagram will work. [EDIT: Read VRG3 comments below....I missed something] Our High and low beam colors are not the same however.

Most likely your lights will be a bit brighter and many have professed good results when done. However this upgrade is really in prep for higher wattage bulbs.

I've never tried this, but with the lights on and the car idling put a voltmeter on the headlight lead on the back of the connector. Then put the tester on the battery positive. The larger the difference, the greater the oppotunity to improve the wiring.

Re: Headlight upgrade wiring diagram

Posted: Sat Feb 11, 2012 4:35 am
by kimokalihi
Oh yeah, gonna try that.

Re: Headlight upgrade wiring diagram

Posted: Sat Feb 11, 2012 8:55 am
by georryan
Ah, I should have prefaced that I'm putting in my EDM glass headlights, although, I do believe you could do this to your stock ones as well. I seem to recall vrg3 talking about doing that. You may see a difference, but the way the stock headlamps disperse the light still hurt the results.

Re: Headlight upgrade wiring diagram

Posted: Sun Feb 12, 2012 6:44 am
by vrg3
That diagram will not work. Our stock headlight circuit is ground-switched; VW's are switched on the hot side.

What you need to change is what you do with the wires going to terminal 85 of the relays. Instead of connecting them to a chassis ground, you have to connect them to the common wire of the stock headlight connector. The rest of the diagram will work fine, but, like PhyrraM says, the wire colors won't match.

You will see a huge increase in light output if you do this upgrade. You can do just one side first if I you want to see for yourself.

You're right that doing this modification with stock North American pre-facelift headlights will not make them work well; there's nothing you can do to make them work well other than replace them with well-designed lights. The European lights you're putting in will be very good though.

Also, I'd recommend throwing in a pair of GE Nighthawk bulbs. They are pretty much the most effective stock-wattage bulbs you can put in the Euro-spec lights (or the stock American 92-94 lights, for that matter).

Re: Headlight upgrade wiring diagram

Posted: Mon Feb 13, 2012 12:40 am
by georryan
Vikash,

By saying the common headlight wire, do you mean the yellow line or the black one? I assume yellow, since the black one is for the high beam?

Do we have a wiring diagram somewhere for this that hasn't been lost due to hosting changes?

Re: Headlight upgrade wiring diagram

Posted: Mon Feb 13, 2012 5:44 am
by vrg3
I don't know the wire colors for pre-facelifts. I know that on post-facelifts, common is blue/white, high beam is red, and low beam is yellow/blue.

To find the common wire, unplug your headlight connector, turn the headlight switch on, and check to see which of the three wires has +12v on it. That's the common wire.

Re: Headlight upgrade wiring diagram

Posted: Mon Feb 13, 2012 11:01 pm
by georryan
Where did you guys who have done this mount the relays?

Re: Headlight upgrade wiring diagram

Posted: Tue Feb 14, 2012 8:36 am
by vrg3
I just made a little bracket out of aluminum from Home Depot to hang the relays right by the headlights (I actually had four relays, basically duplicating the above diagram but separating the left and right headlights). They mounted to one of the headlight's mounting studs. You can see the stud and nut in the middle of the left side of this photo of Josh's: http://www.main.experiencetherave.com/s ... P_2140.JPG

Oh, also, definitely use the alternator rather than the battery for the +12v source. When the car's running, the alternator is what's powering everything. And I would definitely not use a chassis ground. Ground the headlights to the engine. That's what the alternator is grounded to.

Re: Headlight upgrade wiring diagram

Posted: Wed Feb 15, 2012 11:10 pm
by Legacy777
As noted in my PM, I mounted the relays inside the fender area opposite of the battery. You can kind of see where I mounted them in some of the pics on page 2.

http://www.main.experiencetherave.com/s ... age_02.htm

I did hook up the wiring to the battery, but have run additional wiring from the alternator to the battery and added chassis grounds to the engine.

Re: Headlight upgrade wiring diagram

Posted: Mon Apr 23, 2012 8:57 pm
by georryan
So I finally got the headlights all wired in.

I have the glass headlights without the electronic level adjuster, and I have the corner lights/blinkers that have a little protrusion for better visibility.

Basically I salvaged wiring harnesses from the junkyard to create a harness for the blinkers and the city lights so I can easily swap back if I ever need to.

I also bought the wiring conversion kit from Danial Sterling. I used the previously referenced wiring diagram from this post as my source to wire up the harness changing the ground in one of the relay pins to the common wire rather than ground per Vickash's correction.

I ran the power lines from each relay into some fused links, then connected them together after the fuses, and then ran a single wire to the alternator's power.

After driving around with them at night briefly....WOW. All I can say is WOW. The difference (which I knew there would be one) was way beyond my expectation.

I do have a leveler on the passenger side that appears to be broken, so the light angles up on the right hand side instead of being completely being horizontally level.

Here are some pictures of the wiring. I'll have to get some of the actual headlights and corner lights when I get a chance as well.

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Re: Headlight upgrade wiring diagram

Posted: Tue Apr 24, 2012 6:16 pm
by Legacy777
Yeah the lighting difference in the 90-91 cars is just night and day....literally!