Headlight power supply?

[Yorb]

This is driving me up the freaking wall. I have developed an extreme hatred for Nissan's wiring in the early 90's.Where is the headlight power supply that I'm supposed to tap my lighted gauge faces into? I have had zero luck getting them to illuminate. The last time I had some lighted gauge faces in there, I tapped them into the instrument panel dimmer switch, and that worked except that they were very dull, so I thought maybe that was just a bad location. The instructions on my new gauge faces say to connect it to the headlight power supply. Makes sense. Where's that?Someone please help, as my car is undrivable in this condition and I will NEED to drive it by Monday morning. Thank you!

[JNM240]

I routed mine from the drivers side marker. This means tho you have to route it under the fender then thru the firewall. But it works like a charm. Im not sure but there is an illumination wire on your car stereo harness. I dont know for sure if it will light them or if it only sends a signal to the radio to turn its lights on. Might be worth a try. It should be the orange wire on the harness.

[Yorb]

Well thanks for the reply... Sounds like a lot of work though. I'm not sure what you mean by "under the fender" but it sounds like I'm going to need a lot of wire and a contortionist's hat.There MUST a way to follow that same marker line all the way in, and tap into it right at the source. This is pissing me off.If only Nissan had made all the power wires have like, a certain stripe on them or something. But no, it's just a mess of completely randomly colored bright wires. =(

[topless@vabeach]

I wired mine to my headlight on/off switch inside my car. I push my lights on and my gauges where on. This was done on my 78 trans-am. I am guessing its the same on the 240sx. There has to be some type of power on the switch.

[Yorb]

Yeah, that's ideally where I want to do it, so that it comes on with my lights. However, there are only 4 wires there. One's green, one's tan, one's peach, and one's black. I have no idea which one is power. =/Oh yeah and when they come out the other side of the harness, two of them are blue, two are orange. The orange ones have stripes on them, one green, one blue.

[Antjaw]

In response to JNM240's previous post. You dont want to hook the dash lights up to the Car stereo dimmer line. What that actually does is tell your stereo to dim its illumination when the headlights are on. The stereo assumes that if you have your headlights on it must be night, and you dont want a super bright radio lighting up the interior of your car. The best bet would be to hook them up to the headlight switch..those seperate lines you spoke of are for the 2 positions on your headlight knob, the headlights on and the parking lights.. You really want to hook it up to the parking light line, That way 1 click turns on your parking lights and interior ac lights and 2 clicks turns on that plus your headlights... Unfortunatly I have no clue about the color of the wires.. My best suggestion is to clip the lines put em in your mouth in diferent combinations till ya get a good shock.. when ya do.. Those are the ones you want! Hope my babbling made SOME sense.

[Yorb]

Thank you Antjaw! We're in the middle of a surprise ice storm right now so I can't do much, but here's where I was before I read your reply...I disconnected that relay with the 4 wires I was talking about, and tested all the combinations coming from the rest of the car (not from the switch side of the relay), and one pair of them produces a 12V current unfailingly, no matter what the headlight switch is set to. This makes sense, it's just the constant + and - line from the battery. However, when testing the gauges on those same lines, I can't get any illumination response. And the gauges work fine, I can touch them to the terminals on a 9V battery and they light up. Do you happen to know what's going on, before I go back out in the freezing cold?Thanks. =)

[Antjaw]

Yup, I do know whats going on... Those lights in your dash dont run off of 12 volts.. I beleive they run off of 5 +/- volts.. Actually I am supprised hooking them up to 12 volts didnt fry em.. But I guess they have a built in breaker or fail safe.. You need to get a multi meter..find a standard ground.. Like a piece of metal on your car... . then touch each wire with the positive end while turning the headlight knob.. when the multimeter jumps.. you have your wire.. .Wire your positive up to that one..and your ground to wherever is a good ground.. and "theoretically" they should work.. Good luck bud.. By the way..If you dont have a multi meter. go to walmart or radio shack and pick one up for $7 bucks...

[Yorb]

Yeah I was using a multi-meter to test before (that's how I found the 12V constant).That's interesting though, I've always heard that they ran off a 12V supply. But I will take your word for it... Thanks for the help. =) Doesn't look like this ice is going to abate today, so I'll let you know how it goes tomorrow.

[Yorb]

Found it! Thanks again, Antjaw.For people reading this thread, the line you want to tap is a red wire with a blue stripe, coming out of the driver's side of a purple harness/relay right under the headlight/blinker lever. At least that's where it was on my '92 SE.The four wires I mentioned earlier appear to only control the headlights opening and closing.In conclusion, it works great, looks great, except for one thing... The needles are extremely dark at night. Very hard to see. I'm thinking maybe the white paint on them was reflective or something, I don't know. Something to consider for anyone else putting white gauge faces in.Actually, on a related note, my clock doesn't illuminate anymore for some reason. Neither do the A/C, heater, etc. They used to light up, but haven't in months... My clock stopped lighting up a few weeks ago. Anybody know what that could be?