after driving for about 30-45 minutes my head lights and interior lights go turn off while driving then turn back on after 2-4 min why help thanks

 

Something is drawing excessive current, and the circuit breaker which feeds the lighting opens the circuit, because it is detecting over-current. When it cools, it resets itself and the lights come back on.


Or, the circuit breaker itself is malfunctioning. It is easily replaced as a first try at solving the problem. If a new breaker does the same thing, the cause for excess current flow must be found. imp

 

had Circuit breakers been invented yet? Okay okay....But I'm almost certain that one did not exist in a 66 OEM. can you point to it in a wiring diagram??

Its probably the switch getting hot and somehow opening up...That sounds far fetched but unless you can find that breaker for me I suspect it maybe a better answer.

-Gun

 

thanks for the help will look into it

 

Ford has used circuit beakers instead of fuses for headlamps and park/turn/brake lights since before I can remember. Look below:





Read under "Headlight Switch":

 

Okay so the breaker is actually integrated into the headlight switch? They are not separate parts?

 

I believe that is correct, for the entire Ford line. IOW, not replaceable separately. But, circuit breakers rarely go "bad". Same thing shown in my 1972 Shop Manual which covers even Pinto, all used circuit breakers for headlights and park/turn/brake lights. Later, "modern" Fords, I have not checked, but reasonable to expect same.


It's good-thinking actually. Ya got lights on only when it's dark out, something goes wrong for whatever reason, draws too much current, a blown fuse to be found in darkness, good luck. Circuit breaker resets itself (non-manual reset). imp

 

It is in the light switch

 

This is good to know.
Thanks!

 

definitely the switch id replace it see if you can find a NOS motorcraft replacement. if not youll have to go with a parts house brand