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Headlight low beams

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Old Jan 25, 2023 | 05:46 PM
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Headlight low beams

So, I don't have low beams on my 84 f250 6.9, is there some fuse or ground that might go out? I already replaced the dimmer switch, but that's not the source of it. (High beams work just fine)
 
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Old Jan 26, 2023 | 08:29 AM
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check the bulbs, the low circuit may be bad.
and the plug going into the dimmer switch may be bad. being on the floor the plug and wires will collect a lot of dirt and water causing corrosion in the terminals, and wires. i lost the headlights on my 88. when i took the switch out the plug and wires fell apart. i had to cut back close to a foot to find good wire to splice a new plug in.
 
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Old Jan 26, 2023 | 11:14 AM
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Originally Posted by tjc transport
check the bulbs, the low circuit may be bad.
and the plug going into the dimmer switch may be bad. being on the floor the plug and wires will collect a lot of dirt and water causing corrosion in the terminals, and wires. i lost the headlights on my 88. when i took the switch out the plug and wires fell apart. i had to cut back close to a foot to find good wire to splice a new plug in.

I have new headlights on it, but I haven't checked the plug, I'll do that and see if it helps
 
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Old Jan 28, 2023 | 11:22 AM
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Originally Posted by Junktownbill99
I have new headlights on it, but I haven't checked the plug, I'll do that and see if it helps
Checked the wire, seems to be fine. :/
 
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Old May 24, 2023 | 07:45 PM
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Did you ever get this fixed? I recently had this issue with my low beams on an 89 7.3 F350. That era of Fords used the single bulb for both High/Low beam, meaning that they shared a ground through the bulb. I checked for power at the lights and found that the low beams weren't getting any power. Tested it back to the dimmer switch, it wasn't working properly so no power was going to the low beam wires. Worked after replacing the dimmer switch.

Here is a diagram similar to the one I used for the testing: https://www.chanish.org/wp-content/u..._diagram_4.gif
 
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Old May 24, 2023 | 10:52 PM
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Originally Posted by german_dragoon
Did you ever get this fixed? I recently had this issue with my low beams on an 89 7.3 F350. That era of Fords used the single bulb for both High/Low beam, meaning that they shared a ground through the bulb. I checked for power at the lights and found that the low beams weren't getting any power. Tested it back to the dimmer switch, it wasn't working properly so no power was going to the low beam wires. Worked after replacing the dimmer switch.

Here is a diagram similar to the one I used for the testing: https://www.chanish.org/wp-content/u..._diagram_4.gif
So... It sounds like the dimmer switch was your problem. Personally, I believe my wiring is a little loose, especially when it's very cold. Mine seem to work good now. Also, if you get those led headlights, it doesn't all come in through one bulb, yet they just plug right in. My advice, just make sure your wires are clean and tight and well grounded, and you should have no problems, (maybe check the headlight switch if the problem persists)

These are my lows, highs are all the LEDs on
 
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