Headlight Switch?

[Fordsandguns]

On my way home Thursday night my running lights and my instrument lights went out. It was a blown fuse. Turn signals, brake and flashers still work. Headlights too. But if I put a fuse in it just blows it.
Couldn't find any shorted wiring or anything that seems to be the culprit.
What do you guys think? Headlight switch?
I've noticed a few times over the last couple days when I pull the switch that it takes a second or two for the headlights to come on, so I'm thinking that's the cause.

 

[typ4]

Headlight switch and dimmer switch could cause problems.
Headlights are not fused, brake and flashers are on #8 iirc turn sigs are ignition powered and fused.

A dash light socket will blow the tail fuse and the obvious, taillight wiring.

 

[87crewdually]

I would say the switch is the best possibility for giving you problems. Remember the switch has the dimmer built into it which sounds like it may of shorted out on yours resulting in no cluster lights and blown fuse. You could unplug the switch and power up each circuit to see if they all work with out the switch hooked up.
Also if you have any trailer plug or add-ons check for shorted connections.

 

[nappy nate]

When you check the switch take a good look at the electrical socket plugged in to it. Its notorious for getting hot and failing along with the switch since the headlight are not run through a relay.

 

[subway]

When you check the switch take a good look at the electrical socket plugged in to it. Its notorious for getting hot and failing along with the switch since the headlight are not run through a relay.

what he said, its a worthy upgrade to run the headlights off a set of relays especially if this turns out to be the problem.

 

[Fordsandguns]

I had planned on ordering one of the headlight harness from LMC, just haven't gotten around to it yet. I guess this is the motivation I need!
Can I just set up some toggles until I get the harness? I have a spare switch but I don't want to put it in and maybe have it go out before I get the harness.

Thanks for all the replies!

 

[Sycostang67]

I have found that the wire coming from the headlight plug for the marker/dash lights likes to melt. I had to replace that wire on my 85, everything still worked but all the wires were melting together. I had the dash out of the truck which is the only reason I found it. I was also parting out a 1990 F-250 and found the same wire was melting on it as well. It was even melting the plug head.

 

[MIDNIGHT RIDER]

Unscrew the fuse-block from the floor and turn it over, exposing a big *** of much too small truck-burning wires.

Amongst this big *** of wires is a very skinny light tan colored wire that will burn/melt itself out of it's insulation, causing all manner of lighting grief.

I am not sure, but it may very well be the same wire of which Sycostang speaks of.


On my 1985, I happened to look outside one night and it was lit up like Christmas.

I am not a light leaver-onner kind of guy, but I thought that maybe in some lapse of concentration I possibly could have left them ON.

When I went to turn the lights OFF, the switch was already in the OFF position.

That light tan wire had melted itself into an always HOT wire and was powering the markers.

 

[Sycostang67]

Unscrew the fuse-block from the floor and turn it over, exposing a big *** of much too small truck-burning wires.

Amongst this big *** of wires is a very skinny light tan colored wire that will burn/melt itself out of it's insulation, causing all manner of lighting grief.

I am not sure, but it may very well be the same wire of which Sycostang speaks of.


On my 1985, I happened to look outside one night and it was lit up like Christmas.

I am not a light leaver-onner kind of guy, but I thought that maybe in some lapse of concentration I possibly could have left them ON.

When I went to turn the lights OFF, the switch was already in the OFF position.

That light tan wire had melted itself into an always HOT wire and was powering the markers.

That would be the one. On my 85 I had to replace that wire from the headlight switch all the way to the fuse block. Most of the insulation had melted away leaving the wire exposed. I was really surprised it never caused any problems.

 

[Fordsandguns]

Well I found it. After hours of looking. And it wasn't the switch or plug or the wiring there. That little tan wire looks fine.
It turned out to be a pinched wire under the center markers on the back. My dad put them on while i was at work. We were trying to get the truck together because it was my only wheels. I guess he was just hurrying and didn't notice. I'm surprised it took this long to wear through and short out.
I will be putting a relay mod on it soon so hopefully that little tan wire never gets the chance to go postal on my truck!

Midnight Rider, I need to take a trip and come visit so I can set up my truck with some of the mods you've done to yours!
I've read some of your posts talking about it and think you have some good ideas.

 

[MIDNIGHT RIDER]

Midnight Rider, I need to take a trip and come visit so I can set up my truck with some of the mods you've done to yours!
I've read some of your posts talking about it and think you have some good ideas.

Awwwwww, it ain't nothing special, really.


Thanks for the compliment.

 

[Fordsandguns]

Awwwwww, it ain't nothing special, really.


Thanks for the compliment.

Hey, I like my ford trucks but it ain't any secret that their factory wiring sucks! Anything that can be done to make it better is insurance against being stuck on the side of the road.
I really liked the way you described having your auxiliary lighting ran through the dimmer switch so that they can be turned off just by dimming the headlights.
My problem is that I don't grasp things from a description well enough to copy it until i have worked on that part. I just can't get a mental picture unless I know where everything is in the first place.

 

[MIDNIGHT RIDER]

My problem is that I don't grasp things from a description well enough to copy it until i have worked on that part. I just can't get a mental picture unless I know where everything is in the first place.

And I can't explain anything worth a darn, nor draw anything recognizable, or do pictures.

I don't know where my electrical and mechanical abilities came from, the school of hard knocks I guess ; it sure wasn't from either side of my family tree going back several generations .

 

[Hyde]

I had the same problem that had me running loops for a while, all it was turned out to be a messed up contact on the taillight bulb.

 

[Fordsandguns]

Yeah, electrical issues are NOT fun. It took me several hours to find it. I was looking for a bad contact like you mentioned when I decided to pull the center markers off and have a look see. BINGO! There it was.