21 custom

Got the 1500 oem fog light kit for my 2500. Everything is compatible. Also bought an oem fog light harness part#84859045. Plugged that into the pigtail coming off the right front headlight harness. The wiring is there coming out of the bcm into the fusebox and from the fuse box to the fog light harness pigtail. Installed everything. GM says it’s not compatible with the 2500. Have to get it programmed to recognize the switch. Currently only parking lights come on with the fog light switch. I’d like to see if the dealership can even do it. Any gm techs out there that would know if it is possible? I have an authorization code. Wams may also be an option but they’re ship in only. Onboard flashing would be ideal.