I apologize in advance if this has been answered a million times before but I'm new here and couldn't find the answer doing a forum search.

I recenlty bought a 1990 F150 4.9L AT LB 2WD that had no headlights. Since all the other lights worked, I guessed it was a headlight switch. After replacing that, I still have the exact same problem, no headlights. The tailights, all four blinker lights, the dash lights, interior lights etc all work fine.

I did also check the fusible links by the battery that run to the solenoid and they seem to be fine. also installed a new headlight bulb in case of the off chance that both filaments in both bulbs were bad.

Could it be a ground issue and if so where is the ground for both front headlights?

Is there a fuse or relay other then under the dash (that fuse is good)?

Could a bad floor mounted dimmer switch cause both high & low beam headlights to not work?

Any other ideas?

Thanks again in advance for your help!

JT
jtmi@comcast.net

 

The grounds are on the inner fenders or core support near each headlight. There is no fuse for the headlights - the circuit breaker built into the switch is fed by a fusible link at the starter relay. Yes, the beam select switch could be the fault. Is it plugged in fully?