Chevy and GMC Duramax Diesel Forum - Reply to Topic
2007.5 + (GMT 900) Non Powertrain--New Body Style-- Discussion 07.5 - 2010 Topics Not related to the Powertrain, interior, suspensions, body, wheels, tires, ect.

Thread: LMM Fog Light Circuit Diagram? Reply to Thread
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  Topic Review (Newest First)
11-18-2010 09:47 AM
steveannisa Hey guys,
Could you not jump the TAN/WHT wire and the DK GRN/WHT wire? this will give you regular control fo the fog lights in the low beam and make them come on while on high beam right? since it is a ground signal from the BCM I would not think it would hurt to have the two jumpered but if you were concerned you could alway diode isolate each signal.
03-28-2010 08:40 AM
08GMCLMM Any other ideas? I've been trying to think of a way to make this work for a while and can't come up with anything.
03-28-2010 07:27 AM
Retired Fire Captain exactly. I must admit after pulling it apart and checking the wrong switch, I thought the BCM had gone bad. I pulled the whole thing apart only to realize I was pushing the nterior light cancellation button. Too funny
03-27-2010 08:53 PM
Convoyduel (forehead slap)...

As soon as I started reading your post, I realized the issue. Thus far, I had not appreciated the fact that the interior light cancellation button above it is a on-off switch but the fog light switch is in-fact a momentary switch.
03-27-2010 10:16 AM
Retired Fire Captain OK Guys;
I took the dash apart today and checked the fog light switch. Bypassing the BCM (Switch to relay,) Will NOT work The fog light switch is a MOMENTARY switch. It only closes while the switch is depressed.
The next trick to try will be fooling the BCM to think that the high beams are not on! The other possibility would be to run a separate switch for the fog lights or have the BCM reprogrammed.
Sorry for the bad news guys!
03-18-2010 04:28 PM
08lmm/white keep us posted as to how this turns out. I just put in BFXenon 3000K Fogs in and would like to be able to run them with the high beams on as well as with the low beams.
03-18-2010 12:03 PM
Retired Fire Captain My concern is that the Dash Indicator lamp for the fog lights is also driven by the BCM. Bypassing the BCM would disable the dash indicator light. Your diagram is sound!
03-17-2010 08:17 PM
Len Todd Maybe the confusion is becasue the schematic shows a Dark Green/White wire (Versus Dark Green/Black) that goes from the BCM to the Fog Lamps' replay coil. Or, am I missing something here?
03-17-2010 07:01 PM
Convoyduel I'm not sure where you get that the headlight low/high circuit is part of the fog light circuit. They are powered and switched separately. The only interface is within the module. Disconnecting the wires as I proposed will made the module think the fog lights are in the off position.
03-15-2010 08:44 AM
cainer70 anyone else have a take on this?? i think connecting the green/black is gonna screw the headlight and highbeams and they wont work properly
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