High beam headlight wiring upgrade info and write up. Graphics rich.

[Nick Gustas]

Interest in my previous post prompted me to do more testing and document the process a little.

I left off with this picture:

as the picture says, the only difference is the voltage delivered to the bulb. This was done with 80watt philips bulbs.

I did more testing before I completed the upgrade.


Stock bulbs and wires with a battery voltage of 13.55v yielded 12.07v on the passengers side, and 12.16v on the drivers side. That's enough drop to make an upgrade worthwhile even at 55w

In this pic, battery voltage was 13.6v, stock wiring was used on both sides, The right bulb is an 80w bulb, the left is 55w stock. the 80w side had a voltage od 11.95v and the 55w side had 12.2v


Here, we see what would happen with a wiring upgrade and stock bulbs. Battery voltage was 13.48, passengers side is a stock 55w bulb with stock wiring recieving 12.12v drivers side is a stock 55w bulb with a wiring upgrade delivering 13.47v

neat eh?

Here I have an 80w bulb on stock wiring on the right side, on the left is a 55w stock bulb running upgraded wiring. Battery voltage was 13.48v 80w pass side was 12.10v 55w drivers side was 13.43v


THe final comparison of this madness is a 55w stock bulb+stock wiring on the right side, and an 80w+upgrade on the left. battery voltage was 13.48, 55w right voltage was 12.10, 80w left voltage was 13.43


How-to writeup follows


Danger!! See this post first!


You will need 16 female spade? connectors and 8 male connectors. two relays, two 10-12ga fuse holders, two 20 amp breakers, two butt splice connectors, and 4 ring end thingys. 16feet or so of 10ga automotive stranded wire, and plenty of heat shrink tubing.


You should pick a high class relay with a well-known name if at all possible. I chose this fine brand:




As you can see, this luxury relay had a mounting tab and extra power out tang that were in the way. I removed them with this fine knockoff of a high speed cutoff tool.





I applied double sided foam tape to the side of the relay adjacent to the spare terminal I removed:


Then I had a snack


I mounted the relay here, just behind a ledge on the side of the housing, make sure to leave space for the autolevel guts to move, I think I left enough, I sure hope so.


Now we need to make the wires that go from the old high beam bulb plug to the relay activation terminals, I used 18ga wire for this as flexibility is nice.




This wire is about 2 inches long, made of 10ga wire, and goes from the relay to the bulb.




The relay power and bulb ground wires should be bent like this to allow slack for strain reduction on the connectors as well as to allow opening of the housing door


The housing door needs two small holes drilled in it so the wires can pass, these need to be sealed.


After running the wires through the holes, put a male connector on each end so as to allow easy removal if needed later.



Prepare the breaker by removing the fuse from the holder, trimming the holder and trimming down the legs on the breaker if they are too long.


Splice a length of 10ga wire to the fuse using a waterproof splice.


Using a waterproof ring terminal thingy prepare the fuse to be connected to the battery like this, don't actually connect it till you have connected the other end to the light and connected ground wires.



On the drivers side I connected the ground to the top windshield washer tank bolt using a waterproof ring end connector, on the passengers side the closest solid ground I could find was the negative battery terminal, so I connected there with a ring end connector.



Once you've successfully routed ground and power around the edges of the engine bay, put a waterproof female connector on each one and connect to the male ends coming out of the housings.




Results:




If you made it this far, thank you! It's really late here and I'm tired, thus the odd tone of this. I'll probably revise this a bit for the day crowd, if anyone thinks it's worthy of a tech article I'll take any suggestions you may have, and clean this up quite a bit.

[jyoteen]

Thanks. I plan to do this to my VW which shows the age in terms of light brightness.

Nice snack. Yummy watermelon!!

[Cybernetic_Samurai®]

[S4@last!::Now B7 RS4]

Looks like a lot of work but definately worth it. I will be doing this before the winter.

[tuan]

and it would be great to get brighter fogs! Nice write up btw. To bad I don't like watermelon...

[S4@last!::Now B7 RS4]

[Nick Gustas]

damage yet. cross my fingers on 80+ being safe

I didn't think to test it while I was in there, but I've personally seen some headlamp plastic that a soldering gun won't melt, I hope they used it here.

[Scourge]

[Nick Gustas]

You'd also have to deal with relay mounting and weatherproofing.

First thing to check would be voltage at the fog bulb terminals, audi may have used thicker wire down there. I'd do it, but I never use the fogs except for the 2-3 times a year I might need the rear one on a bad day.

If no one else does it I'll check voltage next time I pull my intercooler grills

[Dan ex S4 owner]