The headlights will only work temporarily before cutting off

DYLANHENSLEY

MEMBER
1983 FORD F-150

After driving at night for the first time in this vehicle I discovered that the headlights will only work temporarily before cutting off, the headlights can be turned back on by pushing the switch back in and turning the headlights back on, but the problem still persists.

The alternator has been tested and is functioning properly, so we have come to the conclusion that the problem is in the wiring but we have not been able to find a wiring diagram for this particular truck

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
42,884 POSTS

Here are the wiring diagrams for the headlight of you truck and the under dash wiring as well.

This guide will show you how to test the wiring and the switch

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-wiring

Please let us know what you find.

Cheers

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Wednesday, March 31st, 2021 AT 7:25 PM

DYLANHENSLEY

MEMBER
3 POSTS

Thank you very much

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Wednesday, March 31st, 2021 AT 7:25 PM

MERLIN2021

MECHANIC
17,250 POSTS

Been my experience that if the dimmer switch is on the floor, that's usually where the problem is! Your welcome Dylan.

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Wednesday, March 31st, 2021 AT 7:25 PM

DYLANHENSLEY

MEMBER
3 POSTS

Hey, I was wondering if you could help us figure out how to take the light switch out of the dash if we were to replace it

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Wednesday, March 31st, 2021 AT 7:25 PM

MERLIN2021

MECHANIC
17,250 POSTS

Reach up under the dash, on the side of the switch there is a button, pull the lights out as far as they go, then push the little silver button, pull the knob out, then there is a nut on the front panel around the hole the rod goes into, remove that, remember to unplug the wiring harness first!

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