Fog Light Issue

Black Sun 5.0

Founding Member
Mar 23, 2002
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L.I., N.Y.
Just rebuilt the stang and finally got it running this weekend. No real issues encountered immediately and we had it running on and off throughout the day. Anyway, at the end of the day, we finished hooking everything up and plugging in some miscellaneous items, including the foglights, which worked fine. Next thing we know, the car is cranking but not getting spark. Tried another battery just in case, no dice. We found that the plugs appeared to be fouled and gave them a quick clean-up. We were just barely able now to get the car started and running, so I take off to drive it home. I stall out at a light on the way, and sure enough, the car won't start again. I waited about a minute or two before trying again, the car barely starts again but I'm able to get home. Later on I'm showing my friend the car and I had to move it into the garage, it fires right up, twice, without hesitation. As we're looking at some of the work done, when we get to the fog lights, we find they're not working at all. So, in essence, it appears that the problem started right after plugging in the fog lights, then something burned out, now the starting issue is gone. Anyone want to venture a guess on this one? I assume there is a relay for the fogs, where do I find it?
 
There is no relay for the stock foglights. Many people modify the wiring to add a relay which relieves the load from the headlight switch and multifunction switch.

Check fuse #15 in the diagram, it is a 15 amp fuse.
Diagram courtesy of Tmoss & Stang&2birds
MustangFuseBox.gif


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer, actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

SEE http://www.corral.net/tech/maintenance/foglights.html to fix the problem. The stock wiring isn't up to the job and is overheating. The headlight switch & turn/multifunction switch are affected by Ford's wiring problem. Sometimes it overheats so badly that the plastic shells of the wiring connectors start to melt. This will show you how to add a relay to the fog lights to relieve the overload on the headlight wiring.
 
In OEM form, there is no relay for the fogs.

I'm not sure I see the connection between the fogs and the hard starting.

The first thing to do in any case is pull the codes.

Good luck.
 
Fuse was checked, it's fine, that's why I assumed that there may have been a relay. We had the whole dash apart and was going to install 50resto's fog light repair kit, but it looked as if someone already took care of that - the connectors were clean and marked OK and the #15 circuit looked like it had an even heavier gauge wire than the 12 gauge 50resto recommended. I just figured it was tied to the fogs out of the coincidences of hooking them up, car not starting and the fogs dying and the car runs.
 
Ok, well, since it can't be the fog lights that were affecting the starting of the engine, and the engine is now running, what should I be looking for to resolve this headlight issue? I would like to get them up and running again without starting a fire on my newly painted and reassemble 5.0. Thanks.
 
mine had the same problem I found out that my MFS was bad, the connections at the MFS where the fuse #15 two pinkish reddish wires and where the headlight/foglight main power wire( red/ yellow) meet was melted the switch and the connector was melted.... take the MFS off and see if thats it...
 
You need to go around the wiring and figure out what burned up. WHen it comes to circuitsthat others have added or modified, all bets are off. Even if there is a relay already installed, it's a simple affair to trace the wires and see what gives.

Good luck.
 
You checked all of your connectors both of the headlight connectors and the 3 connectors that connect to the MFS u should take all the connectors out and inspect them, I did it and thats how I found my problem check the connector on the MFS that is in the middle of the two other connectors thats where the headlight and foglight power and fuse # 15 goes to
 
Well, I went to retrieve all the parts to attempt the corral.net foglight fix and found that Radio Shack p/n 64-3067 (moisture resistant tap-in connector) no longer appears to exist. I went to two stores, both told me the same thing and cross referenced in case it was an old part number. I went to Per Boys and Aid Auot, neither of which had a clue. Any suggestions? I'd really like to get this project rolling here. Thanks.
 
Let me ask another question before I order the part (no parts store I've been to has this part): the 3M Moisture Resistant Tap Connector is the one I want, I assume. In the directions it says to place the 250" female blade connector into the tap connector, but from the pic I'm looking at, I don't quite see where it would hook into. Can anyone clarify this for me? Sorry, I'm not an electrical guru here.