Installing after market fog lights

Theory of operation. The bcm monitors the headlamp switch to know what is going on, the bcm then sends voltage to fog lamps, when activated. At the fog lamps two wire connector, the black wire is ground, the other wire is voltage comes from bcm. You can use test light to check voltage and ground with fog lamps turned on. There are codes for fog lamp, the two that I noticed, shorted to voltage or shorted to ground, these are B type codes, manufacturer specific. Check the codes.
I saw two 40 amp fuses going to bcm, those fuses are hot all the time. No specific fog lamp fuse because the voltage comes from bcm. Hope this helps a little. I can only help with testing.

check fuse 19 in underhood fuse box. Check for battery voltage coming into the MF switch on the red/light green wire. Then check for battery voltage on the white/yellow when you turn on the fog lamps. Next, check for battery voltage on terminal B16 in the relay socket after pulling the fog lamp relay

Fog Lamps The fog lamps switch is located in the instrument panel switchbank. Push the fog lamp symbol on the switch to turn on the lamps. The indicator light will glow. Push the ribbed part of the switch to turn them off. The indicator light will go off. Your parking lamps or headlamps must be on for your fog lamps to go on.
http://www.pontiac.com/content/dam/pontiac/northamerica/usa/nscwebsite/en/Home/Owners/Owner_Resources/Manuals/en/us/1999/montana/1999-pontiac-montana-owners-manual.pdf.pdf

Page 2-63 of owners manual

New car day running light is achive only by ecm programming

Ask the dealer

Check your instructions with the fog lamps, I believe you will need to take your car to a dealer to have them activate the fog lamp driver in the Totally Integrated Power Module.

You have a short to ground somewhere in the drl-fog lamp circuit. Check for obvious wiring connector or wiring to drl & fog lamps. check wiring for pinched or broken wires coming from sockets. If you don't find problem, you can trace wiring from lamps to main harnesses and hopefully find source of short.
hope this helps.

i dont think current wiring harness is set up for fog lights but fuse box should have a spot for relay and fuse (although it may or may not have metal leads installed) if your getting parts from ford i ask them if they have wiriring harness for it
if you decide to wire them in yourself i would HIGHLY recomend u put a relay in the system if you dont you will have to use bigger wire tho the whole sytem. with a relay u only have use the bigger wire from relay to lights. You will also have to use a heavy duty switch u will burn up factory switch if dont use a realy

There is a small square "trap door" in each wheel well directly behind the fog lamps. You can pry it open and access the fog lamps. They just twist loose.

Usually there are some areas that have rubber boots for factory equipment/wiring to pass threw. Cut a small notch in the boot and pass your wire threw.