No engine power when headlights on!
 

Ok, I just drove about 40 miles and there is a serious issue with my 2012 Z (2600 miles).

To be fully candid, I wired up my rear foglight yesterday without seemingly any issues. I wired it based on the write-up I did just today in THIS thread.

Anyway. Without the lights on, the car feels normal. When the headlights come on either manually or in the Auto position, there is no power. When I say no power, I'm talking about the amount of power the car has when the traction control kicks in. Just enough to crawl.

After about 10 minutes of driving this way, both the traction loss light and the ABS light came on. I thought to myself "ok, I'll just hit the button to turn off traction control". Well, this turned on the light that sad TC was off, but there was no different result.

Is there any way my foglight install could cause this? I tapped into the green (tail light) and red(brake light) wires from the left tail-light. Grounded to the consolidated ground just in front of that tail-light. The foglight works normal. No dimming of either the foglight or taillight. All connections were soldered and heat shrink tubing applied. All wires were taped in bundles and put in split loom which was further taped end to end. There is no way anything is shorting.

Tomorrow morning I plan to try just removing the bulb from the foglight and seeing if this solves the problem. This is the easiest way I can think of replicating my pre-install state.

I won't have any time to deal with this tonight, but I would really appreciate some feedback on how to jump into this. Or perhaps if there is another known issue.

Logic and probability say it's definitely your foglight install. You've probably made a short somewhere and you're shorting out power to the ECU and it's going into full retard mode (yes, that's a technical term from the Official Nissan Service Manual). No way it's a random coincidence on an otherwise new car, just too unlikely. I'd say try removing your wiring taps (and tape over any exposed sections with electrical tape) and see if the problem goes away (assuming just the bulb doesn't fix it). I haven't done this wiring job and I can't verify exactly how yours looks either, but even if you didn't make a technicality mistake like physically shorting a wire you shouldn't, it could be that you've misunderstood which wires to attach where and now whenever you turn on the headlights (tail-lights), your properly-soldered-and-sealed circuit is just grounding out the positive side with insufficient resistance.

I was able to sneak out and do a quick test. Just removing the bulb was enough to make the problem go away. It seems the circuit itself is the issue rather than an accidental short.

My 90 seconds of googling indicates there is a CK type 7443 bulb that some cars need. I'll have to read up on that some more.

This isn't my first time around automotive electronics, but I'm a bit baffled on this.

Good to hear at least you found the issue

Great help wstar :tup:

:iagree:

glad to hear you got it diagnosed OP :tup:
you never go full retard

Remember Sean Penn, 2001, Sam I Am? He went full retard. Went home empty-handed.

+1

OK. Quick follow up. Looks like I was the one that went full retard, or at least partial retard.

I assumed the black wire was the ground on the 7443 socket. It's not, it's the low light. Green with yellow is the ground, which I should have known.

I should be able to rewire this afternoon.

No kidding, I keep getting annoyed about these color schemes in electrical wires, but it is a type of theft deterrent.

He needed to be disarmed.

The problem is that you tapped both the brake light and tail lights and you caused a short. You linked them somehow. its one or the other. Either you link the Fog light to the Tail lights, Brake lights, Reverse lights but not all together. Unless you do some modification to the Fog light with a two fillament bulb.

:tup:

I have a 2 filament (7443) bulb in a 7443 socket.

See details HERE

I'm going to start updating that post with details on what happened. It's fixed now and I just got back from a quick test ride (with the lights on) to verify all is well. A quick summary is that I was grounding the low light filament, providing running power to the high light filament, and providing braking current to the ground. So basically it worked visually in that it came on with the tail lights and got brighter with the brake lights, but there were were some other issues at the same time.

With the headlights on, I reckon that the ECU "saw" power in the brake light circuit as it is bridged to tail light circuit and the ECU interprested this circumstance as "the brakes are being applied" - the ECU won't permit mnre than nominal sustained throttle opening when it thinks the brakes are applied ... it will let you "blip" the throttle ina heel/toe maneuvre but will not supply sustained throttle opening when it believes you have applied the brakes.