Fog lights not working

[DBcooper]

When I bought my 05 GT, it had an aftermarket grill with the fog lights removed. I finally got around to putting an OEM grill with the factory fog lights back on. I can’t for the life of me get them to work. The under hood fuse and relay are good. The fuse has power going to it. I tried a known good switch out of a buddies car. The fog light symbol on the switch does not illuminate when pulled out. I’ve tried different bulbs. And yes, I’ve tried with the car running. I do not have power at the socket. All of the wires look fine going from the fuse box to the sockets. They’re loomed with the head lights and parking lights and all of those are working just fine.

I replaced my SJB a while back due to water damage. Is there something in there that needs to be reprogrammed in order to get a signal from the switch to lights? Any and all suggestions are appreciated.

 

[DieHarder]

It's a fairly simple circuit. You should be able to trace continuity/voltage thru the circuit using a test light or VOM. The Fog lamp relay should activate/click when the fog lamp switch is pulled (which provides a ground on pin 85 of the relay).

Ford Workshop Service & Repair Manuals - fordrepair.info - 2005 Mustang 2005 Mustang Fog lamps

Ford Workshop Service and Repair Manuals, 2005 Mustang Wiring Diagrams Fog Lamps

iihs.net

 

[DBcooper]

It's a fairly simple circuit. You should be able to trace continuity/voltage thru the circuit using a test light or VOM. The Fog lamp relay should activate/click when the fog lamp switch is pulled (which provides a ground on pin 85 of the relay).

Ford Workshop Service & Repair Manuals - fordrepair.info - 2005 Mustang 2005 Mustang Fog lamps

Ford Workshop Service and Repair Manuals, 2005 Mustang Wiring Diagrams Fog Lamps

iihs.net

Thank you for that diagram. My next step was to check the voltage through the circuit with a test light. I just got to wondering about that new smart junction box. If the used one would have came off of a v6 with no fog lights, I was just wondering if I would need to have ford calibrate it.

 

[DieHarder]

Can't say but my son's '07 v6 didn't come w/fog lights so I sourced an OEM switch, grill and OEM style fog lights and found that the harness already had the connectors in place and hooked it up. Everything worked find..

 

[pass1over]

I added heated seats to my car, the exact same way the factory would of. So I added wires to the existing connectors into the SJB, etc, and everything works as it should. No reprogramming necessary.

 

[Nick W]

I didn't want to make a new post considering this one is close enough to the subject mater.

I have a 2009 GT mustang, the issue is that my fog lights will not turn on. I checked the relay and fuse under the hood with a meter checked #15 in the interior fuse panel I believe that's also for the fog lights from what I have read, it was also good.
Just to be sure I checked the light plugs themselves with my meter and they are not getting power amd they ohm out good. I pulled the light switch from inside the car to make sure I don't have damaged pins or wiring it looked good. ALL other lights interior and exterior are working properly it's just the fog lights. And yes the car ignition was in the on position.

Thank you for the help.

 

[DieHarder]

I didn't want to make a new post considering this one is close enough to the subject mater.

I have a 2009 GT mustang, the issue is that my fog lights will not turn on. I checked the relay and fuse under the hood with a meter checked #15 in the interior fuse panel I believe that's also for the fog lights from what I have read, it was also good.
Just to be sure I checked the light plugs themselves with my meter and they are not getting power amd they ohm out good. I pulled the light switch from inside the car to make sure I don't have damaged pins or wiring it looked good. ALL other lights interior and exterior are working properly it's just the fog lights. And yes the car ignition was in the on position.

Thank you for the help.

Fog Lights Wiring diagram: https://iihs.net/fsm/?d=40&f=Fog Lamps.pdf

Also, here's troubleshooting procedures from the manual: https://iihs.net/fsm/?d=389&f=Fog Lamps.pdf

Follow symptoms chart and Pinpoint Tests "O". Should be able to narrow down the issue using a VOM fairly quickly.

Pinpoint Test O: https://iihs.net/fsm/?d=389&f=Fog Lamps.pdf&p=7

 

[Nick W]

Thank you ill let you know what i find.

 

[07 Boss]

I have the opposite issue. My headlights have not worked in like forever. I did a roadside repair of attaching my fog lights into my HID relays and it's been like that for years. Just never got around to checking on the actual issue. I'm going to have to address it before I try and sell her.

 

[bambam 06]

I have the opposite issue. My headlights have not worked in like forever. I did a roadside repair of attaching my fog lights into my HID relays and it's been like that for years. Just never got around to checking on the actual issue. I'm going to have to address it before I try and sell her.

I had the same problem a few yrs ago, 2006 gt. It was the Ballast that were bad, changed them problem solved.

 

[Autokyrios]

Fogs may not come on if the car isn't on (doesn't have to be started, but switched past ACC to ON). If I had power in the car right now (rebuilding) I'd confirm if that was true or not.

Also, there's a fog lamp relay in the engine bay fuse box. Did you add it and is it good?