High beam failure
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Tuned
Joined: Dec 2011
Posts: 313
Likes: 8
From: Wyotana
High beam failure
Seems that I have gone thru 3 multi-function switches in 3 years!! All 3 have had a high beam failure issue. When I turn the high beams on - all headlights go out! I find it hard to believe that the MFS failed that often so it has to be something else. A buddy said it would be the relay, but I see no relay part listed in the high beam circuit. Is it called something else? Where would this relay be? Under the hood or dash?
Laughing Gas
Joined: Apr 2006
Posts: 1,121
Likes: 267
From: Middle Georgia
So are you saying that you install a new MFS, it works for a while, then it has the same failure?
Is the switch burning out, or maybe a problem at the connector so it works a while after you mess with it then eventually goes bad again?
That does seem like an odd coincidence that they'd fail the same way all three times unless there is a design flaw that causes it. It's not on a Ford, but my little Kia has a problem with it's MFS. Not as serious as your issue, but the fog light circuit failed in the MFS and it's failed in the same way on a lot of this model, but apparently not enough to cause a recall. It was a design flaw where the lead going to the switch was made too short and stresses (eventually breaking) the connection at the switch. Got the parts, but haven't gotten around to fixing it yet.
Is the switch burning out, or maybe a problem at the connector so it works a while after you mess with it then eventually goes bad again?
That does seem like an odd coincidence that they'd fail the same way all three times unless there is a design flaw that causes it. It's not on a Ford, but my little Kia has a problem with it's MFS. Not as serious as your issue, but the fog light circuit failed in the MFS and it's failed in the same way on a lot of this model, but apparently not enough to cause a recall. It was a design flaw where the lead going to the switch was made too short and stresses (eventually breaking) the connection at the switch. Got the parts, but haven't gotten around to fixing it yet.
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Hotshot
Joined: Jan 2004
Posts: 19,768
Likes: 1,082
From: St Louis
Then it's likely the MFS failed again (for whatever reason). There is no relay in the circuit as proposed by your buddy.
If all of the lighting is OEM, then it would pretty much be necessary to dissect the failed switch for more clues as to the repeated failures. If you have non-OEM headlights installed, I'd speculate that they're pulling too much power and the switch is being overloaded.
If all of the lighting is OEM, then it would pretty much be necessary to dissect the failed switch for more clues as to the repeated failures. If you have non-OEM headlights installed, I'd speculate that they're pulling too much power and the switch is being overloaded.
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Laughing Gas
Joined: Apr 2006
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From: Middle Georgia
Freshman User
Joined: Jan 2008
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Likes: 3
Doesn't explain the problem you're having, but I think in general Ford truck don't have solenoids in their headlight harnesses, so everything has to go through the switch. Several companies make kits to add solenoids, primarily to brighten lights up, you can buy theirs or copy them yourself.
These aren't cheap, but better quality than most others and work well:
CE Auto Electric Supply Headlight Relay Kits
These aren't cheap, but better quality than most others and work well:
CE Auto Electric Supply Headlight Relay Kits
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Tuned
Joined: Dec 2011
Posts: 313
Likes: 8
From: Wyotana
The MFS failed once with OEM Halogen lights. I eventually put LED in the headlight positions, and the second MFS failed. Third MFS failed after being there for 2 months. The kicker is; I don't drive this truck much and very little at night especially in the summer. In a year of driving I might only use my headlights/high beams 50 times!
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