Light switch
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From: Moorhead, MN
Light switch
I posted a ? in one of the other spots and have not really received an answer to my question ....well I'll just leave it at that...
On my 89 the low beams don't work, the high beams work the running lights work as do the taillights. The only thing associated with the headlight switch that doesn't work are the low beams. I did check the headlamps and switched them out with my 94 and the lamps are good.
Where do I start looking for my issue, I hate to buy parts just to see if it was the issue, guess that's what stealerships do but it doesn't make it correct.
Can the headlight switch go bad and only not work on the low beams if all the other lights come on with in that position?
Does the light circuit go throught the dimmer switch?
I can only come up with the two switches as the problem point, any other spots to look?
On my 89 the low beams don't work, the high beams work the running lights work as do the taillights. The only thing associated with the headlight switch that doesn't work are the low beams. I did check the headlamps and switched them out with my 94 and the lamps are good.
Where do I start looking for my issue, I hate to buy parts just to see if it was the issue, guess that's what stealerships do but it doesn't make it correct.
Can the headlight switch go bad and only not work on the low beams if all the other lights come on with in that position?
Does the light circuit go throught the dimmer switch?
I can only come up with the two switches as the problem point, any other spots to look?
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Joined: Aug 2009
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From: Phoenix
do you have high beams?
if bulbs are comfirmed good, the circuit path is headlight switch (which has a very weak internal circuit breaker), dimmer switch, and then the lamps themselves.
If the circuit breaker in the headlight goes you will usually get the "flashing ford" symptom...all lights will be on, and the headlights will randomly flash on and off.....this is what usually happens, but I have seen the switches just die completely. a quick and easy way is to see which switch could be failing is to see if your high beams work, if so it is more than likley the headlamp switch itself.
As a side thought and recommendation, I would seriously consider doing the headlight relay mod...In stock form you are running about 10 amps through a thin wire, around the engine compartment twice, with that whole load (which is constant at night) being handled by the switch...its a bad and ineffecient design that both makes the headlight dim, and burns out the switches
if bulbs are comfirmed good, the circuit path is headlight switch (which has a very weak internal circuit breaker), dimmer switch, and then the lamps themselves.
If the circuit breaker in the headlight goes you will usually get the "flashing ford" symptom...all lights will be on, and the headlights will randomly flash on and off.....this is what usually happens, but I have seen the switches just die completely. a quick and easy way is to see which switch could be failing is to see if your high beams work, if so it is more than likley the headlamp switch itself.
As a side thought and recommendation, I would seriously consider doing the headlight relay mod...In stock form you are running about 10 amps through a thin wire, around the engine compartment twice, with that whole load (which is constant at night) being handled by the switch...its a bad and ineffecient design that both makes the headlight dim, and burns out the switches
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From: Moorhead, MN
I purchased the truck this way so I'm not sure how they got to this point however, I do have High beams.
Looks like a trip to the store, will look into the headlight mod.
Thanks
Mike
Looks like a trip to the store, will look into the headlight mod.
Thanks
Mike
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Joined: Aug 2009
Posts: 375
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From: Phoenix
sounds like the dimmer switch. there are 3 wires, a 12+vdc input from the headlight switch and 2 outputs (1 for low beams, 1 for high)...with the headlight swItch on you should be able to connect a meter to the switch and watch the voltage switch between the two wires....if its missing on one theres your problem.
on one of my trucks the po actually cut the low beam headlight wiring and ran an unfused switch directly to the battery (an uninsulated toggle switch left under the hood no less)....i say check the voltages at the dimmer, then look for "interesting" wiring uunder the hood near the headlights themselves.
on one of my trucks the po actually cut the low beam headlight wiring and ran an unfused switch directly to the battery (an uninsulated toggle switch left under the hood no less)....i say check the voltages at the dimmer, then look for "interesting" wiring uunder the hood near the headlights themselves.
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From: Moorhead, MN
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From: Phoenix
seeing as you already replaced the headlight switch, do the relay mod....it will keep your switch happy for years to come
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From: Nutter Fort, WV
https://www.ford-trucks.com/article/...ay_System.html
https://www.ford-trucks.com/article/...r_Brights.html
Both are good, I used 10 AWG wire for my headlight mod instead of the 14 or 16 mentioned in the articles.
https://www.ford-trucks.com/article/...r_Brights.html
Both are good, I used 10 AWG wire for my headlight mod instead of the 14 or 16 mentioned in the articles.
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