First off, I located the service manual for my car on this site which was invaluable for understanding the workings of the DRL:
This helped me zero in on the likely culprit – the “Daytime Light Control Unit” (and to find it in the engine compartment).
A couple of taps on the unit caused the headlights to flicker, so that’s got to be a good sign that the problem is there.
A call to the local dealer – $270 for a replacement. Ouch. A call to the local auto wreckers – no G35’s. So back to the internet and search for Daytime Light Control Unit and there are a whole load of posts on the Nissan forums about the unit and cracked solder connections, and that it is not too difficult to find and repair. So I did ….
Here are a series of photos that show the steps. The research took 4 days, the repair took about 30 minutes.
Here is the location of the unit in the engine compartment
A little closer after removing it (easy)
Now for the fun part – open it up. There are 4 small plastic tabs that can be moved with a small screw driver,
Here are the insides – pretty simple for $270!!!
And the backside with all the soldering. See the suspicious area?
And zooming in …. Yup, that is a cracked solder connection. I applied some more solder with a soldering iron, and it’s good as new. Reassembled everything and put it back in the car. Yes!!!
Original Thread: Strange Headlight Problem – Canadian 2004 G35x