Fog Lights Do Not Turn On

Hawk03

Hawk03

Dutch User
Joined
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LS
2000 V8
My fog lights have not been turning on when the headlights are on and the fog light switch is on. I have checked the fuse and relay and both are good. I’ve taken the bulbs out and they do not appear to be blown. I thought it might have something to do with having a remote start (Viper 771) but that only hooks up to the headlight wire from the switch harness. I’m not sure where to go from here.
Does anybody have any ideas?
Thanks.

This has been going on for a few weeks and the brights were off.
 
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Hmmm... this one is a stump-er...

The order of things I would check:
Switch position
Dims
Fuse
Bulbs
Relay
switch
wiring

But the problem is... it would appear as though you've checked almost all of those; try checking the switch... make sure it's still functioning. After that, wiring is your only option. Doesn't seem likely though.
 
I have the same issue occasionally. I think it's my switch going out because everything else is working fine.
 
Don't want to be insulting, but you DO know that the foglights won't work with the brights on?
KS
 
cammerfe said:
Don't want to be insulting, but you DO know that the foglights won't work with the brights on?
KS
Click to expand...

I know my brights were off and they still didn't work. For the time being mine are working now tho. Who knows with this car anymore.
 
If you figure it out, post the results. I have the same problem sometimes they will come on, and sometimes only 1 will come on. I checked the wiring for shorts and exposures but nothing.
 
Just one coming on?!?! That HAS to be a wiring problem! MAYBE relay if the two sides use two relays... but I highly doubt that.
 
I installed a new head light switch and that did not fix the problem. I tested the fuse connector with a multi-meter and there was not any volts coming through, the one next to it(the horn) had 12. I also checked the light connectors and there was no volts registering there either. I'm thinking the problem is between the switch and the fuse box but I am not sure where to look.

Does anybody have any suggestions on where to look? Or how the wires are ran under the dash, firewall or are there other connections?
 
I'll check when I get home. I believe that all the switches go to the computers (PCM, REM, FEM, ...etc) abd those computers performs the switching.
 
Quik LS said:
I'll check when I get home. I believe that all the switches go to the computers (PCM, REM, FEM, ...etc) abd those computers performs the switching.
Click to expand...

I still have not found an answer to this problem. I looked around the web and found someone with a similar problem and was told to disconnect the anti-theft device and it will solve the problem. He was told the anti-theft and fogs lights are connected in some way. Could this be true? If so where is the anti-theft to disconnect it.
I have no power to the fog light connector or fuse.

Any help is appreciated.

Thanks

Here is the link:
http://www.justanswer.com/questions/1d9ba-2000-lincoln-ls-3-0-engine
 
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Probably not in your case, but my LS had damaged ground wiring, which made the FEM unable to activate the aux pump (no heat @ idle), horn (even after replacing the borked clockspring) and foglights.

The fix was expensive - $400 wiring job at the dealership.
 
Here's some diagrams to help you trouble shoot. You can see here that these modern cars do not use switches to turn on lights - more they use switches to tell the computers to turn on lights....

switches.jpg


lights.jpg
 
Yup. In my case, I figured it was something to with the FEM after fixing the clockspring and manually energizing the horn and foglight relays (didn't know about the aux pump at the time).
Boy, am I glad that it wasn't the FEM that was borked. That would've been mucho dinero!
 
WhoBeDaPlaya said:
Yup. In my case, I figured it was something to with the FEM after fixing the clockspring and manually energizing the horn and foglight relays (didn't know about the aux pump at the time).
Boy, am I glad that it wasn't the FEM that was borked. That would've been mucho dinero!
Click to expand...

Looks like I have a bad ground wire too. I can turn the fog lights on by adding another grounded switch to the relay. I'd much rather have the ability to turn them on by the head light switch but this seems to be a cheaper way.

Do you know where the ground went bad at?
 
The FEM grounds the relay to turn on the fog lights. It does this via an electronic circuit inside the FEM. The wiring to the FEM could be defective, the FEM could be defective, or one of the inputs to the FEM could be incorrect.
 
Well, to dig this up from the way past, my brother and I worked for 2 days trying to trace the wire from the switch to the FEM. After tearing apart the fender liners and looking where the all the wires go, we decided to try to make the fogs work off the headlights. We then tapped off the Negative lead at the passenger headlight and connected it to the Black/Green wire that triggers the negative lead of the foglight relay. You can not control the foglight independently, but you can still use the factory switch. The foglights come on the same time as the headlights, we have not confirmed if the foglights turn off when the brights are on, I assume they will not.
 
I know on the pass side, there is a large ground right behind the headlight. You have to look for it, I didn't look on the drivers side. 2 big wires go into the ground and 3 or 4 small ones come out.
 
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