Light switch problem

[BrandonMag]

I was having intermittent problems with my dash lights (running lights) not coming on after I pulled the headlight switch to the fully extended postition. Also, a couple of times they just stopped working while I was driving down the road. I hit the dash near the headlight switch and they came on.

The problem got worse, so I assumed the headlight switch had gone bad. I removed it from the dash and found that one of the nine (or so) metal prongs in it had overheated and was now loose. I sprayed it down with Kroil, reinstalled it and it worked fine. After a couple of weeks, the intermittent problem reoccurred, only now it was worse.
Assuming that the switch had reached the end of it's useful life, I went to the local Ford dealership and bought a new headlight switch. I installed it, pulled the knob out, and while the headlights work fine, my dash lights wouldn't come on. Now I have to gently ease the knob back past the first position (running lights) but before the last postition (headlights and running lights), jockey it around a bit before I can get BOTH the parking lights (dash lights) and headlights to come on at the same time. It's a PITA, and I'm not sure what to do to fix it.

BTW, I've also noticed that something makes a clicking sound underneath the hood by the brake master cylinder when I manage to finagle the running lights on.

 

[icanfixall]

You really need to the headlite modification. That takes plenty of amps out from going thru the switch. Sometimes the main wire harness plug behind the switch will melt and catch fire. Plenty of trucks have been lost from this type of electrical fire... The other location this happens is the engine maine wireing harness plug. The yellow glow plug wires melt the plug when they get resistance in them... that builds heat... Heat makes fire... The under hood wireing burns up... So easily preventable too.... Both of them....

 

[MIDNIGHT RIDER]

It reads like you got a dud switch, plus the problems you already had.

Access the bottom of the fuse-block and inspect that skinny TAN wire, which you will find to have melted itself out of it's insulation.

Sooner or later, it will now melt it's naked self into some other wires and then is when weird things start to happen.

Do as Gary suggested and get the headlights on relays.

While you are at it, go ahead and do the marker/parking-lights on relays also.

Did you replace the headlight switch pig-tail with a new one ??

Like all factory wiring jobs, Ford wiring is way under-par.

 

[BrandonMag]

Did you replace the headlight switch pig-tail with a new one ??

No, and the pigtail is slightly melted from where the original switch over heated at one point. But when I say slightly, I mean slightly...

It looks like I'm going to have to take the dash apart again and go over everything with a fine-tooth comb. Yay.

 

[bghnkinf350]

Not to bring up an old thread, but did you find out what was wrong?

I have the same problem, and it is driving me crazy. I did the headlight mod, and am on my third Autozone switch (all lifetime warranty). I had a blown fuse for the tail lights. I replaced it, but the problem is still hitting my truck.

 

[Dsl_Dog_Treat]

If the headlight switch pigtail shows ANY sign of melting, replace the pigtail ASAP.

As already said, the wiring is sub par and the relay mods are a much needed upgrade to minimize chances of a thermonuclear meltdown.

 

[austin]

Hmm... had this problem come up after I removed my bed for paint. Now I just man handle the switch, but I guess I'll get around to checking all of the fuses and doing the switch mod.

 

[BrandonMag]

Not to bring up an old thread, but did you find out what was wrong?

No, I checked the Motorcraft switch I got from the dealer with my multi-meter according to the schematic in my Chilton's, and all of the positions checked out fine.

So I'm pretty sure something's going on with my wiring; I just haven't had time to completely tear the dash apart, find the problem, fix it and do the relay mod. I'm thinking about completely eliminating the headlights and running lights (dash lights) from being controlled by the headlight switch and just running them to their own dedicated switches, but I haven't made up my mind on exactly what I want to do yet.

I've still gotta time the truck, that's next on my to-do list. Soon though, I'll have this problem figured out and I'll let you know what I found.