Hi Guys,
I have a problem with the headlights going out on my 93 F250. It does it on either high or low beam but you can keep them on by pulling up the lever to " flash" position. Seems to me that the problem is in the steering column switch but I'm not sure and don't have a wiring diagram. Sure hate to buy a switch I don't need but dark is coming earlier and the problem is getting worse. Any words of wisdom?

Thanks

 

The headlights have a some kind of circuit breaker that will overheat if there is an improper ground or obstructed wiring. When it overheats, the lights will shut off to prevent damaging the headlight itself. Once the breaker cools, the lights come back on. That is what I was told after my lights would go out when my highs were on. Hasn't happened in a good while but whenever I was driving slow on a gravel road with highs on it would cut out after a few miles. I haven't driven any gravel in a while so I don't know if its fixed or not. Could be a number of things but I hope this helps a little...

-Dave

 

I know on the earlier years [my 86] it was [is] a common problem...easy fix, replace your headlight switch and should be ok. lol

 

My rig is a 1991 F250 7.3l. I don't know if replacing the switch would help for my year...

 

Dave, I don't really know for sure, but if the symptons are the same ie, flickering, go off for no reason, you turn off the lights then turn them back on and they work, thoughts of going to a priest to talk about your truck cause you think its possesed, ya I think it's worth a shot! lol

 

HAHA, I'd better get my money back from that priest (aka the dealership) eh? I will check the wiring and switch connections to see if there is something out of sorts. It only happens when my highs are on so it may be the floor switch going bad...

 

Dave, there is an old thread about replacing headlght wiring, I belive Dave S has it in his truck...how bout it Mr Sponaugle?

 

Here's a good one. I just give the floor dimmer a little kick from the side and they pop back on. Not a permanant solution. I think I'll look to the junk yard for a new old dimmer switch. Would still like to see the rewiring plan.

 

Ford used rather small wire for the headlight circuit.
I used a pair of relays for off road lights that get power from the batteries to run my headlights. I used the stock headlight wiring to trigger the relays. I also upgraded my headlights to APC diamond lights with Silverstar bulbs. Now I can see where I am going much better.

Find the light wires on the drivers side inner fender.
You will be installing two relays, one for low beam, one for high beam.
Cut the wires leaving the wire coming from the cab side long enough to connect to the relay trigger terminal.
I installed my relays right behind the washer and coolant recovery tanks on my 86.
Attach a 10 AWG wire to the power terminal of both relays and the other end to the battery positive terminal.
Attach a ground wire to each relay on the correct terminal, I ran mine to the battery.
Attach a 10 AWG wire to each relay on the power out terminal. This wire has to run to each headlight and connect to the correct terminal for either low or high beam.
I also happened to find heavy duty headlight sockets at Advance Auto that has much heavier wire than the stock units Ford used.
I also upgraded the ground wire size to each headlight, I also ran this wire to the battery.

This takes all the amperage draw off the stock headlight switch which did cause switch failures in the earlier model trucks. Also the correct amount of amperage supplied to the headlights makes them last longer and burn brighter.

You can still buy floor mounted dimmer switches and the cost is about 10 dollars.
But they do not seem to last very long in my truck, probably has something to do with the amount of mud that gets tracked in mine this time of year.

 

Well I finally got around to fixing my lights. And as usual Murphy helped .

Since they work for a while , I put them on high beam and waited for them to go out. Ok, out they go and the fun begins. Pulled the dash and all of the connections, checked for voltage and continuity all over H#*% and back. finally got to the plowlight / headlight selector switch, and the switch was bad. Good but not so good. The lights went out the first time when I was driving it home from Georgia where I bought it, and I put the plowlights on 2 months later.

Back to the drawing board. Started the truck, jumped the bad switch, turned on the lights and went to split firewood. About 30 min later the lights started to flicker. Back to work!

Well guys it was the headlight switch, I guess the flickering made it seem like the flasher was doing something, or maybe there was some sort of feedback. Anyway I replaced the switch [MADE IN MEXICO!!!] with one [ Motorcraft] from an 89 F250 that I'm parting out and the gods are happy. While I'm replacing the plowlight switch I'm gonna do Dave's relay retrofit to avoid future problems.

Now all I have to do is fix the plastic parts on the dash.........

If I were any happier I'd fart!

 

I also did some work on my flickering headlights. It gets dark here at 5:30 now and people think I'm crazy flashing my lights down the hi-way.

Replaced the dimmer switch first. No help. Then pulled out the haynes for the headlamp switch. Popped off the ***** and fastened it in . Did'nt even break any dash parts.

I started looking at the wiring under the hood. Prior owner already installed relays for the rear lights. None on the head lights. Maybe after I get my fuel sender straightened out I'll try the headlight relays.

Thanks to Dave S for the good instructions.

 

mine started the flickering thing a few months ago come to find out it had been so long since i had the headlites out that they had growed green and all other types of colors so trying to get them off well i got a few doner trucks so i just cut the plugs off and put in new works great now

 

i have 93 f350 the plastic block the wires are in that connects to light s/w MELTS that is the problem

 

It is explained well on post # 9 by Dave S. The wires are to small for the amount of amps the headlights pull. So it melts your switch. You can just replace you switch and may have no problems. Thats what I did. The previous owner of my truck already install extra relays for the rear lights. Suppose its to help with the trailer lights.
The mighty ford still rides strong !! ( with headlights)
Good luck Turboidi

 

turboidi,
Welcome to FTE and the IDI diesel forum.