I added plow lights to my truck and something quit when I had the high beams all on at once. All 4 shut off. Low beams still working. Any ideas what I fried or where to check? Its a 99 F250 superduty.

 

You probably blew the fuse for the high-beams (or the wiring or the MFS...).

See owner's manual for fuse listing.

 

From the online manual looks like the fuse for the HI beams (#16) also protects the instrument cluster, which is working fine. CRAP!

 

F16 only protects the high-beam circuit. The high-beam indicator is all that runs off it in the cluster, nothing else.

Does the flash-to-pass work?

 

yeah on a plow setup you are supposed to have the 6 pin 3 way toggle switch with only 2 on truck or 2 on plow on at a time, i would be willing to say that somewhere in the line you cooked a main feed wire trying to power 4 highbeams off of a 2 light circuit... if you cant get the 6 pin 3 way switch you can always get a 3 pin 3 way switch and run a relay to power the plow lights off of 1 setting on the 3 way switch and the other position on the 3 way switch to the factory headlights, of course with the 3 pin 3 way you will have to wire the toggle switch after your high/low beam switch there... hope you good luck in finding the current issue, but easiest thing i can think is to get a cheap test light if you dont have one and start testing for power from the mfs back towards the battery/fuse block

 

It was the fuse

 

the purpose of the fuses is to do exaclty what happened. When you draw to many amps on a circuit, the fuse blows BEFORE the wire gets hot and melts.

 

Before I start a new thread, can someone here explain how to remove the headlight enclosure? I see the clip on the top but cannot get it unclipped. (if that's even the right way to remove them)

 

the two clips pull straight up. sometimes they are "stuck". push in on the front of the headlight a little, then try to pull up.

 

I too have no high beam headlights. I just stopped working! Pass won't work, looks like #16 fuse is fine. Fuses 26/28 also appear fine. High beam indicator works and lights up blue. Help!

 

It helps if you actually identify your specific vehicle as there are variations between some years and some models.

Since the cluster indicator works, there is an open circuit at or "downstream" from the splice where that indicator's signal is picked off from the high-beam circuit. That rules out the MFS and all the fuses.

 

Sorry about that. I guess having just started here and placed my info into sign up, I didn't think about model etc.

My truck is 2000 F-150 Lariet flair side 5.4 motor. Since the fuses are good, Got any idea what else it be?

 

See previous post. You'll have to troubleshoot it from there.

 

Thanks. I read your answer wrong I guess. I'll have to have someone look at it I guess. Have no clue.

 

Ronny, if you have power to the head light switch, and power out of it to the fuse, and power out of it toward the headlights.... there is a splice in the wire somewhere by the firewall that connects the high beam indicator light. What SHO89 is saying is the wire from the fuse to the bulb is probably bad, and probably near that splice... THis assumes you have power out of the fuse, and no power at the head light plug, and bulbs are known to be good ??