2000 Ford F350 Super Duty--high beams don't work

[jolycu]

Hello,
I'm posting this for my nephew who asked me to see if I could find some help for him.
He has the above pickup with a 6 speed 7.3L Power Stroke engine. The low beam on the headlights works fine, but the high beams won't work at all. He has replaced the dimmer switch and has replaced the headlights, but they still won't work. What should he check next?

Thanks for any help you can provide!

[jonmark1985]

Make sure you are getting 12 volts on the high beam side of the harness.

[mark v]

And look for any broken grounds. Check the bulbs to make sure the high beams work, maybe he replaced the bulbs with the wrong bulbs?

[jolycu]

Thanks for your suggestions jonmark1985 and mark v. I have passed them on to my nephew. Regarding the bulbs, he is positive he has the right ones. If it turns out that he's not getting 12 volts at the harness, what would be the cause of that, a break or short in the wiring or something else?

Thanks again for the help guys!

[mark v]

Yes it could be a short or a fuse of some sort either being a regular fuse or fuesable link. Lately it has been headlight switches being a problem on the forum.

[ABE]

Originally Posted by jolycu

Hello,
I'm posting this for my nephew who asked me to see if I could find some help for him.
He has the above pickup with a 6 speed 7.3L Power Stroke engine. The low beam on the headlights works fine, but the high beams won't work at all. He has replaced the dimmer switch and has replaced the headlights, but they still won't work. What should he check next?

Thanks for any help you can provide!

By dimmer switch do you mean the multi-function switch on the steering column? If this switch is pulled to the steering wheel in the "flash to pass" position the high beams and indicator and low beams should work from a power source that is not the headlight switch. Does this put the high beams on?