Fog lights won't cut on
01-14-2014, 12:51 AM
#1
Teching In
Thread Starter
Join Date: Mar 2011
Location: Sacramento
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Fog lights won't cut on I have a 2000 camaro z28 5.7 I got it a couple years ago fog lights never worked I just started messing with it. I bought new lights and a new fog light relay and they still don't cut on does anyone know what else could be the problem?
01-14-2014, 07:16 AM
#2
Gee Doctor, my arm hurts... do you think you can fix it over the phone? 
Much more information is needed to help diagnose this issue. Did you buy original equipment replacement fog lights or aftermarket? Did you replace the factory fog light relay in the junction box or one in an aftermarket harness? When you replaced the lamps did you put in new bulbs or just swap the original bulbs into the new housings? Do you have a test light or multimeter?
The factory fog lights are powered off the TAIL LPS fuse in the dash fuse panel so if the rest of your lights are working, you can eliminate the fuse as a source of the problem. Does the ON indicator lamp in the fog light switch go on and off properly? If so, you can also eliminate the switch as the problem. However, unlike Firebirds, the indicator light is powered inside the switch so it doesn't give any indication of whether the relay is working.
If you transferred the original bulbs to the new housings, I would guess that you just have two burned out bulbs. Beyond that, you're going to have to do some testing to diagnose the problem. Start at the lamp sockets and work your way backward testing for power when the lamps should be on (i.e. lights on but not high beams). If no power at the lamp sockets then move to the relay and test there.
The brown wire at the relay should have power whenever the lights are on. The yellow wire should have power when the lights are on and the fog light switch is in the on position. The light green wire should show ground as long as the high beams are not on. The purple wire is the relay output to the lamps and will be difficult to test with the relay in place. With a multimeter you can test continuity between the purple wire at the relay and at the bulb sockets to ensure the wire isn't broken someplace but that's about all. Still, if the other tests are successful and you determine the purple wire isn't broken, the relay is the only possible cause.
If any of the tests are unsuccessful then you'll have to start tracing the appropriate wire related to the failure. For example, if the yellow wire has no power but the switch is okay, then you'll have to find the break in the yellow wire someplace between the switch and the relay.
All of the notes above are related to the factory wiring configuration but the testing methods would be similar for an aftermarket setup.
Much more information is needed to help diagnose this issue. Did you buy original equipment replacement fog lights or aftermarket? Did you replace the factory fog light relay in the junction box or one in an aftermarket harness? When you replaced the lamps did you put in new bulbs or just swap the original bulbs into the new housings? Do you have a test light or multimeter?
The factory fog lights are powered off the TAIL LPS fuse in the dash fuse panel so if the rest of your lights are working, you can eliminate the fuse as a source of the problem. Does the ON indicator lamp in the fog light switch go on and off properly? If so, you can also eliminate the switch as the problem. However, unlike Firebirds, the indicator light is powered inside the switch so it doesn't give any indication of whether the relay is working.
If you transferred the original bulbs to the new housings, I would guess that you just have two burned out bulbs. Beyond that, you're going to have to do some testing to diagnose the problem. Start at the lamp sockets and work your way backward testing for power when the lamps should be on (i.e. lights on but not high beams). If no power at the lamp sockets then move to the relay and test there.
The brown wire at the relay should have power whenever the lights are on. The yellow wire should have power when the lights are on and the fog light switch is in the on position. The light green wire should show ground as long as the high beams are not on. The purple wire is the relay output to the lamps and will be difficult to test with the relay in place. With a multimeter you can test continuity between the purple wire at the relay and at the bulb sockets to ensure the wire isn't broken someplace but that's about all. Still, if the other tests are successful and you determine the purple wire isn't broken, the relay is the only possible cause.
If any of the tests are unsuccessful then you'll have to start tracing the appropriate wire related to the failure. For example, if the yellow wire has no power but the switch is okay, then you'll have to find the break in the yellow wire someplace between the switch and the relay.
All of the notes above are related to the factory wiring configuration but the testing methods would be similar for an aftermarket setup.
01-14-2014, 12:39 PM
#3
Teching In
Thread Starter
Join Date: Mar 2011
Location: Sacramento
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Yea I just bought the stock bulbs no aftermarket stuff just trying to get the lights on. I replaced the junction box. I put the bulbs in the original housing. Thanks for your reply I'm going to give everything you said a try.
