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Does anyone have the wiring diagram for the electrical circuit for the headlights? I think I have a fried relay. All my fuses are good for the lights but I only have running lights, no headlamps. Also the highbeam light on the dash is stuck on no matter what position I have the headswitch in. The truck is an 03 F-350 Crew Cab Short bed with the 7.3L. Any help would be greating appreciated!
 

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Unless you have "automatic on" headlights, there isn't a relay for them. The power runs from the fuse box, thru the main light switch, thru the multifunction switch on the steering columns, then thru another fuse, to the headlamps.

Are you sure you checked the fuses downstream of the multifunction switch? If they're good, then I think I'd concentrate on the multifunction switch.

If you still have problems, PM me, and I may be able to help out.
 

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This is not true about there being no relay.....at least on all trucks. My '01 has two relays, one for the low beams and one for the high beams located under the hood along the passenger fender. I just had a similar problem with mine about 2 months ago. My high beams quit working and the relay was the problem. Everyone told me that there was no relay but I know for a fact that there is in my truck. If you need some help finding the klebel just let me know. Also, I had a hard time finding the replacement relay but I can give you the part # for it if you find that is the problem. I am at work now and I am temporarily transferred to another firehouse so I will have the info once I get back. Let me know.
 

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If you trace down the problem and determine that it is a bad relay that I have mentioned, here is some info that will help you get the right relay:

Advanced Auto (GP Sorensen) Part # 41-5093 Price $16.46

Pep Boys Part # R 4136 Price $25.09

NAPA Part # AR374 Price $24.17

When mine went bad all three of these places (as well as the dealer) checked in their trusty computers and told me exactly what everyone else says: There is no headlight relay in these trucks. I finally got a parts guy who recognized the relay and the above part numbers are the numbers I cross referenced after I solved the problem so I could share the info in the event anyone else ever has the same problem. Good luck and let me us know what you figure out.
 

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Unless you have "automatic on" headlights, there isn't a relay for them. The power runs from the fuse box, thru the main light switch, thru the multifunction switch on the steering columns, then thru another fuse, to the headlamps.

Are you sure you checked the fuses downstream of the multifunction switch? If they're good, then I think I'd concentrate on the multifunction switch.

If you still have problems, PM me, and I may be able to help out.
 

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This is not true about there being no relay.....at least on all trucks. My '01 has two relays, one for the low beams and one for the high beams located under the hood along the passenger fender.
The OP was asking about an '03. But it should be very similar to an '01. A stock '01 will NOT have relays for the headlights. Those are add-ons, probably using standard Bosch style relays. That was a common mod. Headlight relay harnesses were available from SUVlights. I built my own and installed it on my '99, using a relay box I got at a wrecking yard. Headlight Relay Mod
If the truck is Canadian, it will however have relays for the Daylight Running Lights, but they are not located by the passenger fender.
Attached are wiring diagrams for '01 Headlights and DRL's
 

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2010 f350 no hi-beams - is there a good schematic or does anyone know which fuses and relays I need to check?
The fuses you need to check are in your owner's manual. That will tell you which to check. If there are any relays on a '10 F350, they would be shown there as well.
 

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Unless you have "automatic on" headlights, there isn't a relay for them. The power runs from the fuse box, thru the main light switch, thru the multifunction switch on the steering columns, then thru another fuse, to the headlamps.

Are you sure you checked the fuses downstream of the multifunction switch? If they're good, then I think I'd concentrate on the multifunction switch.

If you still have problems, PM me, and I may be able to help out.


I have automatic on headlights where is the relay located??????
 

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I have automatic on headlights where is the relay located??????
I have no idea. You didn't tell me what year truck you have. Critical info to get an answer from anyone.
 

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On a 2002 relays controlling the auto headlamps are built into the Vehicle Security Module and are electronic (not replaceable without changing out the VSM.
If you have daytime running lamps, there will be a separate relay box under the hood on the driver's side containing two relays.
Are you having an issue, or just want to know where the relays are?
 

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The OP was asking about an '03. But it should be very similar to an '01. A stock '01 will NOT have relays for the headlights. Those are add-ons, probably using standard Bosch style relays. That was a common mod. Headlight relay harnesses were available from SUVlights. I built my own and installed it on my '99, using a relay box I got at a wrecking yard. Headlight Relay Mod
If the truck is Canadian, it will however have relays for the Daylight Running Lights, but they are not located by the passenger fender.
Attached are wiring diagrams for '01 Headlights and DRL's
Where are the relays if you have automatic lights?
 

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On a 2002 relays controlling the auto headlamps are built into the Vehicle Security Module and are electronic (not replaceable without changing out the VSM.
LIke I said, two posts ago.
 

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LIke I said, two posts ago.
Thank you just saw that. I tested the fuses and there is no voltage there. One of the high beams has .3v
I already tried a new main switch. Is it just a broken wire or the multifunction switch?
03 f250 super duty. No highs or lows. Only have fog lights. Has automatic headlights.
 
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