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Originally Posted by
Nathan_Barstow
What exactly did you do to perform your wire harness upgrade to the headlights? I'm considering doing this as I just ordered some VW MK3 headlights for my NX and am wanting the most efficient, brightest light I can safely achieve. Probably going HID for the low beam projector, but don't know what I want to do for the brights yet.
1. Upgraded, heavier gauge wire from the socket - 12 or 14 ga, some people go heavier.
2. Added a slow fused relay (and I would add a fast fuse to the relay if I was hooking up something unknown to me like the MK3 headlights and maybe even go thicker than 12 ga wire for the power lead).
3. Pull the hot lead from relay straight off the battery for cleaner power, better power.
4. If you want to do it up right add a separate relay for high and low beams (I am talking reg headlights, not HID add-on kits).
5. Either buy plugs for putting things together and/or solder and heat shrink wrap all your connections. Most kits are plug and play but I see not reason to go nuts on that for a single application that does not change.
You can do this two ways - buy a harness upgrade kit already pre-wired which depending on how much power you are pushing through it, might be very expensive. OR, you buy a few 40-50 amp relays (have to double check amps on that), some spools of wire, a box of assorted connectors, and
ideally a fused connection you can hang off the hot side of the battery. The advantage to that is if you do have some bull**** short and pop a fuse, it is a lot easier to replace than the relay (as an in-line fuse, just like if you were running dedicated hot lead for the stereo or whatever).
Check out the pre-wired kits at the link I mentioned before. If you look at the components used then you can probably make a pretty quick decision if you want to roll your own or buy one pre-made (ok, actually two, you need one per side).
I don't have any detailed pics of my setup and it is 14 deg out so don't expect any today, but I will gladly pull off the wire guides and show you how mine was done. It's not complicated. Another benefit is you greatly simplify problems with one light works, the other one doesn't, etc. because each one has its own wiring and usually split between relays for high and low if you want to run something stupid like I do, i.e. 80/65 or 110/80 halogen bulbs, both of which you should check your local laws of course before using as they might not be legal if you live in anywhere in the US but wth, the uber highs are what I was really looking for and I defy someone to say "oh those Tsurus have 65W lows vs. 55W lows". The high beams you cannot miss because you may run 200-220W total vs. the usual 130W total across both sides. So don't say I didn't warn ya!
By no means am I saying this is the best or only place to buy this stuff, but they do a very good job of laying out the stuff frankly you can find for a lot less elsewhere if you don't mind assembling your own.
HEADLIGHT WIRE HARNESS/ SOCKETS & RELAYS suvlights.com HEADLIGHT WIRE HARNESS/ SOCKETS, RELAYS, MISC. PARTS
But even a basic upgrade 9004 wiring kit is at least $30 and serious sets 2, 3, or 4 times that for some relays, wire, plugs, fuses, and other stuff already put together for you in a manner you just might end up pulling some of hit apart anyway (for example if you want your fogs to run with either high or low beam).
Nice thing when you're done besides having lights is if you do a clean job it's really easy to troubleshoot later if something goes wrong. I never have had a problem so I assume that is true because it sounds better and makes sense.
Like I said it is effin cold out and dark so I apologize for the lack of pictures here, but you if you zoom in you can see at least one relay with the white plug coming in from either highs or lows (second one is covered up by the OEM relay box) and where they hook up to my pos battery cable from the trunk near the MAF/intake. I have some cleaning up to do there and would like to have a better setup for where the grounds come together, someday soon...