If you want to make this work using the least amount of time and money possible, all you'd need is a diode and about 4" of wire. The wire needs to have the diode spliced into it, then installed between fuse box pins J4 and A4 with the end of the diode with the line painted on it facing pin A4. The top of the fuse box has the letters and numbers along the edges, kinda like the game Battleship. You'd be doing
this, but the diode MUST be installed. DO NOT just hook up a wire between the two pins as I have in the picture, if you turn on your fog lights without a diode installed (or installed backwards) you can do some serious damage to your BCM. Consider yourself warned
When energized the fog relay pulls 125mA of current (or 1/8 of 1 Amp), I used a 3A/50PIV diode, but anything rated 1A or more should work.
I did mine a little neater, and installed a fuse to protect the BCM just in case the diode decided to fail.
I started by gathering the parts I'd use:
The fuse taps were made for standard size blade fuses, we have the mini size blade fuses, so I needed to use a dremel to trim down the blade a bit so it would fit into the fuse box. I also had to straighten the folded end to make it fit better, then inserted the taps into pins A4 and J4.
To connect the diode, I used 1/4" spades that I pushed on to the ends of the diode, then put a drop of solder on to keep it from working loose. The diode MUST be installed with the white or silver line facing the fog relay at pin A4. DO NOT turn on youg fog lights (with the switch on the turn signal lever) until you verify that turning on the brights also turns on the fogs (to verify the diode is installed correctly):
Since the fog relay only pulls 125mA when energized, I installed a 2 Amp fuse in line with the diode to protect the BCM just in case the diode was to fail. A little heat shrink over the diode, a few more crimp on spade plugs, and this is what the completed jumper looks like:
The jumper installed:
You can ignore the add-a-circuit fuse tap installed in my box, that's how I powered my hidden radar detector
And the end result, all 6 lights on at once:
Fogs only:
If you use 'flash to pass' (or hit the unlock button on the fob):
How it works, and the potential problems if you hook it up wrong:
If you look at the schematics, what you're doing is tapping in to the +12V supply going to the right side high beam bulb (circuit 311) and using it to pull in the relay that turns on the fog lights (circuit 1317). If you were to just connect a wire between those two circuits, or install the diode backwards, when you energized the fog lights you would be trying to turn on your right side high beam bulb using +12V that is coming from the internal logic of the BCM. It may be able to handle the current, but I'm guessing that it can't. Please don't be the one to find out!
Now that I'm done modding the car I think I'm going to give it a much needed bath.
