This problem is beginning to frustrate me. I bought an 01 silverado 2 months ago. Only one fog light was on it because the owner said the other one cracked and he never got around to getting a new one. The existing fog light didnt work but i thought it may need both lights hooked up to work. I bought a new fog light and when i connected everything i still had no fog lights working. I then pulled out the relay and guess and tested jumping the 5 holes. Doing this got them to light up. So i concluded it is either a bad relay or a bad switch. I put a new switch in and still nothing...i tested the wire that plugs into the switch and i had voltage going through it. I then said ok, it must be the relay. Well i just put a new relay in and still nothing. From what i can tell, there is one fog lamp fuse and it is next to the relay. I checked that and its fine. Im out of ideas. Does the car have to be in drive for them to go on or some weird thing like that? Any tips for how to correct or even to diagnose this problem would really be appreciated.
This is an 01 silverado 5.3L Z71. Btw, it has an alarm/remote start. I just thought i should mention that. Thanks.

 

the truck has to be in drive in order for them to turn on..good luck

 

also since u said that you have a remote start alarm..i'm guessing it might be aftermarket? you should check the wiring on that as well because i wired mine wrong and the foglights werent turning on so that might be the problem also...good luck

 

yeah but i didnt install the alarm so i have no idea how it was supposed to be wired. Is there any way to figure out if the alarm is intervening?

 

Do you have the low beams on while testing for operation??

 

yes i have tried pretty much every combination and still nothing.

 

I had a 2000 and installed OEM fog lights. The dealer had to program the computer before they would work. Maybe you have the same situation.