fogs as DRL, auto-on retained

[cybermob2]

anybody been able to mod the fogs to function as DRL, while still retaining auto-headlight-on functionality???i've been staring at diagrams and poking around upside down in my car and my head is beginning to hurt.main reason is for upcoming HID install.

[joatmon]

Just guessing here, putting this out for discussion and not as known fact, and definitely no guarantee:Looks like what controls whether the headlights are on in dim mode or full on mode is pin 1 of the DRL module, which is ground when the low beams are on full, it must be something more than ground when in half dim DRL mode.Perhaps if you cut the wire leading to pin 1 of the DRL module and tied the end that goes to the headlights to the TAIL signal coming out of pin 14 of the DRL module, you would get full bright headlights whenever the tail lights were on, and would never get the half dim DRL through your upcoming HIDs. One concern would be whether or not pin 14 of the DRL module would be able to safely sink enough current to ground from the headlights. Might be better to drop a relay to ground in there somewhere, switched by the TAIL signal.

Attached files

[joatmon]

Then, you could cut the wire coming out of pin 4 of the DRL module, and connect it to the cut wire coming out of pin 1 of the DRL module. That might provide enough ground (through the fog light switch) to activate the fog relay. Whenever the DRL module tried to turn on DRLs or headlights, it would instead turn on the fog lights. You could still turn them off by turning the fog light switch to off.One problem would be if the signal coming out of pin 1 of the DRL module wasn't close enough to ground to activate the FOG relay.Another issue, that may or may not be a problem for you, would be that in the stock config, the fog lights are turned off by the DRL module when the high beams are on, this mod would cause your fog lights, if on, to stay on when the high beams are on. Some people want that, some locations it is supposedly illegal. To get past that you'd have to perhaps come up with another relay to open the circuit whenever the high beams are on.

Attached files

[cybermob2]

interesting... i need to probe some more.i'm half thinking about disabling and adding aftermarket DRL/Auto