Electrical Headlight Switch Issues

Hello,
I'm new to these forums, but have searched around and I can't really find an answer anywhere.
My headlights don't turn on when I pull the headlight knob out all the way. However, if I fiddle with the knob and push it in a little bit they will switch on. Then after driving around and going over a bump they will turn off again.

So I have already changed the headlight switch twice, and even the wiring harness. The problem still exists.

I'm wondering what else it could be. Is it possibly related to the relays, or, fuses?

Also with the switches they don't come with the little knob shaft, could it be related to the this shaft?

With all the switches I have checked for continuity on the B2-R, and B1-H circuits and they have been fine.

Thank you for your time
 
  • Sponsors (?)


Might be real helpful to post the model year of your Mustang. Why? Because in 2004 Ford added an extra wiring harness connector in the back left hand corner of the engine bay. The headlight circuit passes through this wiring harness that's not present in other model years. Water in this area might cause this issue.

Otherwise based upon the reported symptoms, it HAS to be in the headlight switch or the electrical connector to the head light switch.
 
  • Like
Reactions: 1 user