I did the double dinn install with a Pioneer AVHX4600BT using all soldered connections and everything works great except for the dimmer. So when the headlights come on, I don't have any a/c control dash lights, nor does the clock light come on. More concerning, is that my nighttime taillights are out too. Brake lights are okay when the brake is depressed, its just when the headlights go on, the tail lights don't turn on as they should.

I tried cutting the dimmer wire connection (between the PAC unit and Pioneer stereo head) and I still don't have dimmer/taillight functionality. I then disconnected the white connector that goes into the PAC unit, and still don't have dimmer functionality (including taillights).

Re fuses and relays, I checked the two panels near the battery. The first panel next to the battery compartment contain two relays labelled daytime running lights 1 and 2 (which look okay). Then fuse panel with a combination of a few relays, larger fuses with top visible wire, and micro fuses which I checked all of them and appear OK. In side driver panel, I checked the micro fuses which appeared relevant to dimmer/taillights which were all intact.

Btw - I always disconnected the battery when doing wiring.

The dash is torn apart, so any help people are able to provide on a quick basis would be helpful.

Thanks in advance!

 

what year? sedan or coupe?

 

Sorry 2004 g35 sedan rwd

 

OK, your service manuals are here:
http://www.nicoclub.com/FSM/G35/Sedan/2004/
(or maybe here - but should be very similar: http://www.nicoclub.com/FSM/G35/Sedan/2004.5_G35_Sedan/ )

The "lt.pdf" file (that's an "L") shows your lighting circuits and the pic below shows the SIX fuses involved in "Parking, License Plate and Tail Lamps" (Is your license plate lamp also out?)
The file "pg.pdf" is the car's electrical "Power And Ground" circuits.

It takes some digging but these books should allow you to track down what's going on. Most logical would be that you have popped a fuse (or 2) during your install, or possibly lost a ground...

Hope you can find it.

 

Thanks for the response - I'll be sure to check these fuses. But the problem seems to lie more with lack of dimmer functionality. Because brake lights and rear turn signals still work.

Anyone know the wiring for dimmer which should come on when the headlights turn on? Would be good to know which wires to test because there are a host that go to the dimmer roller button on the left side of the dash. Could even run a separate switch if necessary to make this work if I can't isolate the true problem.

 

I think the issue here is more likely something that happened during your double-din install, don't you? In the manual I point to above; "lt.pdf", starting on page 187 is the section called "illumination" which describes all the bits you are having trouble with.

I'll offer you one theory: the part of this circuit which connects to the radio is not radio power, it's only for the radio's dial lights. If you're trying to power your head unit from there it won't work (remember this circuit is on a dimmer). That would also immediately pop a fuse.
Keep looking.

 

Thanks for the help Skyline - I didn't know about the fuses located in the IPDM to the left of the battery under the wiper panel. Ended up being a blown fuse (#71; 10A). Thanks so much for your help and drawing my attention to these wiring diagrams. Love this site.

 

I had the same problem and replacing the blown fuse got me my taillights back, but the dimmer switch still doesn't work. How'd you fix that one?

 

i’m also having the same exact problem, only thing is i’ll switch out the fuse and turn on the headlights and everything will be fine but as soon as i put it in reverse it immediately blows, to my knowledge everything is stock, no noticeable aftermarket parts, and it this problem started after i replaced the fan clutch, don’t think that has anything to do with the problem, but any ideas help!
03 g35 sedan 5AT

 

I would assume u have a short in your reverse light wiring somewhere.

 

I think the reverse lights are on your trunk lid, right? I suggest you check the wires running through the rubber boot from the body to the trunk lid. After years of opening and closing your trunk those wires are likely to fray, break, or short to ground. You should be able to pull the rubber boot back from either end to inspect them.

 

Yep, time to take apart the wiring in the trunk flexible wire loom and I strongly recommend splicing/replacing ALL the wires. When one starts to fail they're pretty much all shot.

Make sure to disconnect your battery before doing this...