KahnBB6

iTrader: (5)

I have followed O.L.T.'s DIY on creating a fog light relay harness for 92-94 SC's:

https://www.clublexus.com/forums/sc-...og-lights.html

Some visual diagrams online which are very similar also helped but the one area that I am stuck on is where to tap my firewall to run the wire for terminal 85 (switch and the trigger signal). I'd really like to know if anyone has found an ideal location to drill for this purpose.

I have my switch mounted and grounded. All I have left to do for the fog light system is to tap my parking lights for the trigger and run my switch signal back to the relay.

Does everyone run their parking light T-Tap from the headlamp harness, then back through the firewall along with their switch signal?

I'd appreciate any help, guys. I'd rather make these last connections after getting some good advice. It's very abbreviated in the writeup.

KahnBB6

iTrader: (5)

I am totally stumped. I could really use some help on this. A picture, even.

I have searched every English language Lexus or Soarer forum on the internet and the most I have gleaned is four locations through the firewall-- all of them baffling:

1) Through the engine harness on the passenger side.

2) Through the steering column boot (there are two boots-- one inside the other?? What is the best way to put a hole through it?)

3) Drill a hole JUST below the throttle cable. I can't figure out how to even fit a drill in in there for the life of me whether it's behind the intake manifold (impossible it seems) or behind the accelerator pedal in the floorboard.

4.) The clutch master cylinder port (I can't use this because my car is a manual).

I spent half a morning fighting to get a bent clothing hanger through the harness cable port in the engine bay and even with the glove box and airbag removed it just wasn't working.

There MUST be a better place to put two 18-gauge wires through the firewall in these cars. The number of boost gauge installations alone should attest to this.

Can anyone please help? I'm about to give up and just tape the switch wires up on my driver's side footwell and forget about it. My foglight system works. I just can't figure out how anyone puts wires through their firewall on an SC without damaging something important.

Cleanshots

iTrader: (2)

ground, just tap into anything that is metal not just firewall.. and for trigger go off the fuse box or lets say the wire for the parking lights, thats what i did there for i can turn the fogs on with one click and second click the headlights come on, and 12v just get from fuse box.. everything get from fuse box, why use extra wire and make it ugly? i went all from fuse box and oem harness..

KahnBB6

iTrader: (5)

For my wiring from the switch:

I found a grounding screw in the footwell for my green wire. I couldn't locate any specific fuse for the parking lights in the engine bay fuse box so I just T-Tapped off the parking light wire off the harness just before the headlight housing-- but this was just to test with the 86 wire and trigger wire hanging out of my doorframe with the hood up.

I've tried to keep my wiring as clean and shielded as possible.

I thought of triggering from the fuse box under the dash but couldn't find an appropriate label (on the panel door) there either.

Cleanshots

iTrader: (2)

i ment fuse box in engine bay.. why wire it to the inside of the car? waste of wire..

KahnBB6

iTrader: (5)

The wire wasn't that expensive to begin with so that didn't concern me. I wired a switch inside of my car so that I could have a convenient means of turning the fog lamps on and off independently of my low beams, not to mention have a way of leaving just the parking lamps on without any other lights on the same active circuit.

Don't most people install an interior switch for fog lamps?

KahnBB6

iTrader: (5)

For anyone else who's got the same issue, I got the suggestion on Supraforums to take off my wheel and fender liner to find a small yellow grommet that goes into the main compartment.

http://www.supraforums.com/forum/sho...lectrical-wire

UR2klose

iTrader: (3)

Just tap into the park lights like Cleanshots said, thats what i did with mine. its better that way because if u run a seperate switch you might forget to turn it off one day and end up killing your battery. you never have to worry about that with the factory switch because it turns off on its own. plus it will look much cleaner than having an aftermarket switch in your interior..

KahnBB6

iTrader: (5)

But wouldn't that mean that every time the parking lights come on, my fog lights would also be on no matter what? I don't want them to always be on even if my low beams are off and only the parking lamps are on.

I already have a little black switch installed and pre-wired on my dash right next to my instrument light dimmer dial. It's pretty clean for aftermarket.

Even if I left the fog switch on, it should be fine. If I leave the car's light stalk in auto-mode the fog lights should cut off anyway once the ignition is cut and the driver's side door is opened.

I've T-Tapped the parking lights at the harness, not at the underhood fuse box.

KahnBB6

iTrader: (5)

With the help of StiCk3 I was able to figure this out and created a DIY for wiring access through the firewall/fender:

https://www.clublexus.com/forums/sc-...ml#post6767890