bobc described below a way to modify the fog light wiring so the OEM foglight switch turns on the foglights any time the parking lights are one (ie: the fog lights can be turned on and off regardless of whether the high or low beams are on). Does anyone know someone in the Boston area that will perform the modification described below? Thanks, NYPrius Uh, did you guys miss my post that we should be able to jumper the SB wire on pin 13 at the ECU to the yellow wire at pin 17 on the ECU? That should still allow the OEM fog switch to turn on the fog without headlights, though you still need tailights, as the fog relay gets its coil power from the taillights. Turns out power coming from the taillight fuse is switched by the ECU with a relay.
You need to use a diode, otherwise the output of the body ECU at pin 17 to the relay will feed back to pin 13, thus bypassing the operation of the fog switch and latching the fogs on. In such a case, the only way to turn them off is to turn off the tail lights.
