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.
I just did the corral's writeup last night as a matter of fact. It took about 5 minutes to do the wiring. The hardest part was fishing the power wire through the firewall in the dark.
It's really a no brainer, just get the relay, the wire, the connectors, follow the directions and you'll be done in no time.
It's really a no brainer, just get the relay, the wire, the connectors, follow the directions and you'll be done in no time.