[USMC7.3]

Hey yall new to the forum. Ive been on a few others but decided to join this one too. ANyways, my 96 f350 has the high beam light indicator go on when i turn my low beams on. Its not fully illuminated but enough to see it. Is my headlight switch bad? What could cause this? When I push the knob in to the runnin/parking lights the light goes away.

 

[Kimber1911]

I spent many years pulling a large stock trailer with lots of lights and finally cooked my headlight switch. I changed it out in the parking lot of an O'Reilly's. Some of the wires were slightly toasted as well.

My headlights were doing some weird things that night. So in answer to your question, yes, I would say a bad headlight switch could be your problem.

 

[action4478]

It may simply be a bad bulb somewhere in the system

 

[madpogue]

Does the indicator light up normally, and do the high beams come on normally, when you switch to high beams? I would think the beam switch contacts within the multifunction swich would be the more likely culprit.

 

[Steve83]

This is caused by at least one bad headlight ground. The current backfeeds through the bulbs' high-beam filaments (which don't get hot enough to glow) and then to the dash indicator. The grounds are the same as shown in this diagram:



Was the truck ever wrecked? Is there battery acid damage on the core support? Any aftermarket wiring mods, like a big bumper, lights, winch...? Has it spent much time near the coast exposed to salt? More information in your profile & signature would be helpful.

 

[USMC7.3]

I have hit a telephone pole about 4 years ago replaced the bumper grill hood and front fenders. Aftermarket headlights as well. And im stationed in beaufort,sc. Right near the ocean and marshes.

 

[madpogue]

If the aftermarket headlights are higher power than stock, you should consider a headlight relay harness. The full current of the headlights goes through the headlight switch and the beam switch, and the headlight switch especially is under-engineered. Pushing even more current through it is, er, not optimal.

 

[USMC7.3]

okay thanks ill look into that. Im gonna change my headlight switch and see what happens tomorrow.

 

[Steve83]

You're wasting money. The headlight switch does NOT connect the high & low circuits, so it can't possibly cause this. Fix the grounds to the core support.

 

[madpogue]

^^^^^ +1; generally, "I'm gonna replace...." should never come before "I'm gonna test/check....." or "I'm gonna inspect.....".