Fog Light Override Without Doing DRL

[jcasemore]

This modification is for the people who do not want their fog lights to go off when the high-beams are on. Instead, you can do the Daytime Running Light (DRL) override posted elsewhere on this site that involves the dark blue wire on the BCM. That mod disables the DRL and allows complete control of the fogs but I wanted my DRL to still work.

The following instructions/pictures are from a 1999 Grand Am SE so it should work for all 99+ models.

The fog lights are controlled by the BCM (Body Control Module) located in the passenger footwell. The input from the fog light switch goes directly into the BCM and than the BCM checks the high-beam state and turns the fogs on or off.

In order to make this mod work you must bypass the BCM. To do so, follow the following steps.

1) Disconnect the negative battery terminal.

2) Remove plastic panel/heater duct from under the dash on the passenger side. OR remove the glove box OR remove both. I just removed the panel underneath.

3) Locate the BCM. It is the large plastic box with three large electrical connectors on it. You can take it off it’s mount by sliding it to the drivers side(or was it passenger? I have to check), towards the hood and than pull the side closest to you down.
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0824Mediumcopy.jpg


4) There are 3 plugs on the BCM. You can unclip the blue pieces if you need to. In the connector closest to you is a dark green/white wire. This is the wire which turns on the relay for the fog lights. In the farthest connector (pink one) there is an orange wire. This is the input from the fog light switch. Be careful to choose the correct orange wire!
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0815Mediumcopy.jpg
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0816Mediumcopy.jpg

5) Cut both wires off close to the BCM. After taping or shrink-wrapping the wires on the BCM side, connect the wires together on the wire loom side. Solder and shrink-wrap or tape them together.
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0819Mediumcopy.jpg
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0822Medium.jpg

6) Plug the connectors back into the BCM. Reattach the BCM to it’s bracket. Replace the glove box and/or panels. Reconnect Battery.

The steps up to this point have made the fog lights turn on with the switch even with the lights off and ignition off so I gave the fog lights switched power.

I tried to open the fuse box to rewire it inside with no luck so I installed a jumper wire on the outside.

I took out the 10A fog light fuse and using a battery charger, blew the fuse. This disconnects the constant power. Since I don’t have a sunroof I replaced the 20A sunroof fuse with a 10A and used a jumper wire to jumper over to the right side of the fog light fuse. This allows switched power while still protected by the correct size fuse. When doing this make sure the jumper wire is far enough into the hole to stay in. Then place the fuse back into it’s spot. The fuse should fit tight but should slide in without a ton of force. This is a temporary jumper until I can figure out how to get the fuse box open.

http://i145.photobucket.com/albums/r233/jcasemore/IMG_0979Medium.jpg
http://i145.photobucket.com/albums/r233/jcasemore/IMG_0985Mediumcopy.jpg

Good Luck.

[canadian_racer]

Thanks, good write up and great pics.

[layton_brian]

what if i have a sunroof what should i do

[jcasemore]

Do you have any fuses there for options you don't have?

[oldbroken]

Technically speaking, you would more than likely be perfectly fine jumping from the sunroof fuse even if you have the sunroof. Worst case scenario is that you blow a fuse, right? and if that happens up the fuse to a 15a. good luck.
Just throwing out a different option all together...why not get switched power from the ignition harness? that is a large gauge wire, hit that., and throw in an in-line fuse if you really want to get fancy.

good luck.

[jcasemore]

I wanted to reuse the same fog light relay and wiring so I had to do it the way I did with burning out the fuse and feeding in power there. I took the whole fuse panel out to try and wire power into the relay from the back but I could not figure out how to take apart the fuse box itself without breaking it so I rigged it up until I can figure out how to take the fuse box itself.

[oldbroken]

yeah, those fuse boxes can be tricky. when it gets warmer outside im going to have a lot of projects to do, and ill see if i cant figure it out. somebody put it together after all, it must come apart... Nothing a little epoxy cant fix.

[beauboy76]

So its not gonna hurt anything to go ahead and use the sunroof fuse if I have a sunroof right?

[jcasemore]

I wouldn't use that fuse because the fog lamp wiring is only rated at 10 amps where the fuse on the sunroof is 20 amps. Try and find another fuse location that is unused and switched power.