Headlights only work on high beam

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Jul 15, 2010 | 11:19 PM

Budman1962

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From: Montana

Headlights only work on high beam

I bought a 97 f150 stepside. I have been working on a few problems on the truck. One problem I can't figure out is the headlights. There is no power going to them on low beam. Is there a fuse or relay that could be out. I don't have an owners manual. Thanks

Jul 16, 2010 | 06:21 AM

93 mix 'n match

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From: Montague, NJ

there is a relay. go to autozone and buy a haynes manual.

Jul 16, 2010 | 06:24 AM

Budman1962

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From: Montana

Thanks for the reply. Is there a separate relay for high and low beam?

Jul 16, 2010 | 06:28 AM

93 mix 'n match

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From: Montague, NJ

im not sure, but i think so. id go look but mines at the alignment shop.

Jul 16, 2010 | 09:36 AM

steve(ill)

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read page 209--- then download the book

http://www.motorcraftservice.com/pub.../02f12og4e.pdf

Jul 16, 2010 | 03:47 PM

projectSHO89

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From: St Louis

Quote:

Originally Posted by 93 mix 'n match

there is a relay. go to autozone and buy a haynes manual.

Uh, NO!. There is no relay in the low-beam (or high-beam) circuit on a 97.

The output of the MFS (Rd/Bk wire) splits to two separate fuses (under-dash F28 and F26) that individually protect the left and right low-beam headlamp circuit. There is nothing else in the circuit.

Check the output of the MFS at the two fuses.

Jul 16, 2010 | 11:12 PM

Budman1962

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From: Montana

Thanks for the replies. I checked the fuses and they are ok. Tomorrow I will check the voltage at the fuses. If nothing there I will disassemble the MFS.

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Jul 17, 2010 | 08:46 AM

projectSHO89

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From: St Louis

Yep, there is a chance that both bulbs have gone. The voltage check at the two fuses will give him guidance on which half of the circuit has the fault.

Jul 17, 2010 | 11:08 AM

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Budman1962

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From: Montana

No power to ether fuse 26 or 28. I checked it with the head light switch on. I will open up the MFS next.

Jul 17, 2010 | 12:14 PM

#11

Budman1962

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From: Montana

Fixed !! I disassembled the MFS and cleaned all the contacts with a scotch brite pad and electronic cleaner. Then I put a thin coat of dielectric grease and resembled it. It is working great. Thanks everyone for the help.
Budman