Duraswede
06-07-2008, 15:49
Hi, i have a little problem, on my GMC i have the DRL and twilight sentinel, and i would like to modify this system so that the foglamps+ parking lamps come on when it's getting dark enough for the DRL to go off..
Now it switches from DRL to headlamps when the switch is in Auto position, and what i would like to do is to replace the headlamp-on signal with a foglamp-on signal...
Because when the DRL goes off, according to my opinion it's still not dark enough to use the headlamps, so it would be better to use the foglamps then, and manually turn on the headlamps when it gets darker, and then i would like that the foglamps go off when i turn on the headlamps, because it's illegal to have both low beam and fog lamps here.
I looked at the wiring diagrams in my service manual but i found out that all the switches sends signals to the BCM and when all the programmed conditions are met then the BCM sends out a signal to the appropriate relays, so there's not much i can tap into.
And i would also like to disconnect the key reminder chime because it drives me crazy, and i was searching after the source for this sound to disconnect it, but found out that it comes trough the speakers, so again, there ain't much i can do about it. (if i dont disconnect the speakers of course:D)
I have made this kind of light controls on my other vehicles before, but only with relays and diodes, i have a high level of traditional electrical skills but electronic control modules is nothing that i can modify, i know how it works basically, and i have built simple transistor circuits but nothing digital, so i understand that the only choice i have here is to let someone make a reprogramming of the BCM, but before i start to search after someone who can do it, i would like to know if it's even possible? well i know that it's possible for GM-engineers, but i dont think they will do it for me..;)
Now it switches from DRL to headlamps when the switch is in Auto position, and what i would like to do is to replace the headlamp-on signal with a foglamp-on signal...
Because when the DRL goes off, according to my opinion it's still not dark enough to use the headlamps, so it would be better to use the foglamps then, and manually turn on the headlamps when it gets darker, and then i would like that the foglamps go off when i turn on the headlamps, because it's illegal to have both low beam and fog lamps here.
I looked at the wiring diagrams in my service manual but i found out that all the switches sends signals to the BCM and when all the programmed conditions are met then the BCM sends out a signal to the appropriate relays, so there's not much i can tap into.
And i would also like to disconnect the key reminder chime because it drives me crazy, and i was searching after the source for this sound to disconnect it, but found out that it comes trough the speakers, so again, there ain't much i can do about it. (if i dont disconnect the speakers of course:D)
I have made this kind of light controls on my other vehicles before, but only with relays and diodes, i have a high level of traditional electrical skills but electronic control modules is nothing that i can modify, i know how it works basically, and i have built simple transistor circuits but nothing digital, so i understand that the only choice i have here is to let someone make a reprogramming of the BCM, but before i start to search after someone who can do it, i would like to know if it's even possible? well i know that it's possible for GM-engineers, but i dont think they will do it for me..;)