I'm looking for a mod for a 2003 Sunfire. When the high beams are turned on, the fog lights are automatically shut off. Does anyone know how to disable this? (and why GM does this?)

I'm also looking for a mod to shorten or eliminate the automatic dimming time of the dome light when the key is out.

both of these things are computer controlled, and there's no changing them, so unless you know a little about electronics, stop right here.

on all cars by law, the fogs are supposed to turn off when the high beams are turned on, not just GM vehicles (ive seen it on other cars too).

the dimming time is also controlled by the computer, there is NO way to change that.

as for the fogs, you COULD wire a relay to the positive output of the high beam wire to switch on when the high beams are on, thereby adding power to the fogs once again (kinda like switching the pass through 87a on a relay to then activating it for power to go through 87).



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- Sold my beloved J in April 2010 -

Or you could route the relay trigger wire to the parking light positive. If you do follow that route, I cannot emphasize enough: Fuse the trigger wire as close to the parking light positive as possible. A little 5 amp fuse will work.

You may have to run that to the current switch on the dash. Unfortunately, this is where my experience comes to a grinding halt, as no car I've owned has had factory installed fogs, so if anyone else wants to pick up from here, have at it.

The fog lights would be on as long as the parking lights are on.

You might want to check your state's law to see how many forward facing lights are legal.

Example:

Revised Code of Washington State - Section 46.37.270

(1) At all times specified in RCW 46.37.020, at least two lighted lamps shall be displayed, one on each side at the front of every motor vehicle, except when such vehicle is parked subject to the regulations governing lights on parked vehicles.

(2) Whenever a motor vehicle equipped with head lamps as herein required is also equipped with any auxiliary lamps or a spot lamp or any other lamp on the front thereof projecting a beam of intensity greater than three hundred candlepower, not more than a total of two of any such additional lamps on the front of a vehicle shall be lighted at any one time when upon a highway.

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So as long as they are under 300 candles and you are a resident of Washington State, can be on at all times regardless.