2003 G35 Sedan

Hello everyone, we are having an issue where the tail lamp fuse (10A) blows immediately anytime the headlamps are turned on. Here are some actions we've taken with troubleshooting, all of which have resulted in the fuse blowing immediately when the head lamp switch is turned on.

1. Removed head lamps

2. Disconnected tail lamps

3. Removed all fuses except the tail lamp fuse from nuder the cowl

4. Removed license plate bulb & checked wiring

5. Checked all wiring along the left side of the motor under the air intake.

6. Removed the amplifier, inline fuse from battery

7. Disconnected power to the relays that control auxiliary fans

So as stated above all of these items are currently out of / disconnected from power source within the car & the fuse still blows. The next stop is to learn how to use the OHM reader to try and trace this down...any insight, guidance or thoughts on this issue would be appreciated.

 

Take a look under the car and make sure someone didn't wire in a hookup for a trailer hitch. It's possible that a previous owner used it to pull a small trailer and the wiring harness from that is shorting out from rusted connections caused by water immersion.

Does your car have a 3rd brake light in the rear window or spoiler? Don't forget to disconnect and check that too.

Other than that, plug in one tail light cluster at a time with the other side disconnected and anything else on that circuit disconnected, and cross check each ground and hot for continuity to try to see if there is a short. Then do the same with anything else on that circuit with everything else disconnected.

Do your interior trunk lights work? I know the interior trunk lights on the coupes are big problem because the harness going to that bulb is too short and it frays and shorts out... .not sure if this is also a problem on the sedan or not. I'm not even sure if those are on the same circuit or not, but am just throwing out out there as a possibility.

 

Neither the tail lights or head lamps are are currently connected & it's still blowing the fuse. The trunk light is working but I will check that as well as the 3rd brake light.

 

same issue did you find out what it was.???

 

Most likely a direct short somewhere.