My wife bought me a set and there very close to the same shape as stock. I was wondering has anyone hooked up diffrent lights to the factory harness? Or should i just use the piaa harness and start new? If so where is a safe place to go through the firewall? Thanks!

What is the wattage of the bulbs? Normally I would say that you should run new wiring, even though each headlight has it's own 15A circuit, which at 12V, could supply 180W of power easily. My biggest concern is the OEM wiring. A lot of OEM wiring is very small. Assuming the wire runs in that circuit are a conservative estimated length of 10', with a 15A fuse, that wiring should be no smaller than 12 gauge. Needless to say, the OEM headlamp wiring is not 12 gauge. It's probably not even 14 gauge. So it'd be in your best interest to run new wiring in a situation where the new bulbs will use more power than the one's they're replacing. The safest and easiest way to do this would be to use the power wires for the OEM bulbs to power relays, which will in turn send power to the headlights. I'd run a single piece of 8 gauge wire (with an inline fuse just after the connection to the battery) to the open side terminals (terminal #87) at a pair of 40A relays, the relay coils (terminal #86) will be powered by the high and low beam wires from one of the OEM headlight harnesses. One relay will be both low beams and one will be both high beams. Ground the relay coils (terminal #85). Connect terminal #30 on the low beam relay to both low beam terminals for the new bulbs and terminal #30 on the high beam relay to both high beam terminals. I'd run new grounds for the headlights as those are also undersized and possibly corroded.

"Your electrical advisor" indeed! LOL. Rob, did that come right off the top of your electrical brain? :D

And, as long as we're discussing.... My factory fogs haven't worked in a while, I was going to go with the Courtesy upgraded lights (or PIAA), if I do the Courtesy upgrade/replacement, should I follow the above procedure as well?

Thanks! :cool:

"Your electrical advisor" indeed! LOL. Rob, did that come right off the top of your electrical brain? :D

And, as long as we're discussing.... My factory fogs haven't worked in a while, I was going to go with the Courtesy upgraded lights (or PIAA), if I do the Courtesy upgrade/replacement, should I follow the above procedure as well?

Thanks! :cool:


X2.. and i didn't understand a word of what Rob said.... :squint:

You guys don't seem to understand. The back page of my FSM is torn off from use and the electrical foldouts and the entire electrical section is considerably worn. I get a hard on for this stuff, I'm telling ya! Why do you think I did that cluster swap write-up that took me days to do when I had no need for the information that it ended up providing? Same reason I've got a cable driven tach cluster sitting in the garage and plan to do a cable driven to electronic speedo wiring cross reference. Because eat this shit up! ;)

Some of that was off the top of my head. I had to use Ohm's law and a wire size calculator to determine some things, but other than that. I'd use that same setup if I was upgrading lights to anything that draws more current, and uses more wattage than what it's replacing. For fogs though you wouldn't need a relay, just possibly up the wire size by replacing the wire from the OEM fuse to the relay and from the relay to the lights, along with new grounds.

As usual Rob is spot on when it comes to electrical. Even if the bulbs are not higher wattage, rewiring the headlights with relays and heavy wire is a very good idea. In fact, even with stock wattage bulbs, you can greatly improve the output of any bulbs by rewiring w/ relays. I am in the process of doing this with the Tsuru headlight upgrade.

im glad i understand everything rob is talking about.

<< worked as an installer for 2.5 yrs

i should upgrade my wiring.

THey are 55 watters i beleive. Ill just put in all the piaa stuff ive never had a problem in the past. Ill just wrap up my factory fogs for safe keeping. SLap em back on in 20 years when i do a full resto...lol. Whats a good place to go throgh the firewall? And thanks for the advice rob. I need to muck with my headlight. The bright on the passenger side still dont work when i turn on brights.