quartz headlights on 1966 mustang

'66427coupe

New Member
Nov 17, 2004
14
0
0
connecticut
hello all,

i have a problem with my mustang headlights shutting off when high beams are lit, the low beams also seem to be quite dim, i am assuming that the wiring isn't heavy enough to supply the voltage to power these quartz style bulbs. these bulbs are replacable like the new style headlights.

does anyone have any ideas how to solve this problem? i was thinking a relay may help but i am not that great with electrical and am not sure how to go about wiring it. or should i just put regular sealed beam headlights back in? :shrug:

BTW the wiring harness is in excellent condition.

thanks in advance for any help...
 
You are pulling too much amps through your dimmer switch. Full current is running though the dimmer switch which it was not designed to handle. When it heats up the contacts pull away from each other and your lights go off. When the contacts cool down the head light start working again. Been there, done that and did not like the ride! I bought a head light wiring harness from "Painless wiring" that was designed for the early model Mustangs to solve this issue. Check out their website.
 
Yup...that's right! It took me awhile to figure that out when I changed my headlights. Put the lights and dimmer on relay circuits and you'll be working fine.

I'm sure if you search, you'll find a more definitive explanation and possibly a link to some wiring diagrams.
 
thehueypilot said:
You are pulling too much amps through your dimmer switch. Full current is running though the dimmer switch which it was not designed to handle. When it heats up the contacts pull away from each other and your lights go off. When the contacts cool down the head light start working again. Been there, done that and did not like the ride! I bought a head light wiring harness from "Painless wiring" that was designed for the early model Mustangs to solve this issue. Check out their website.


I don't think the dimmer switch is at fault here. The actions you describe are exactly what the circuit breaker in the headlight switch is there to do. The headlight switch circuit breaker is shutting down the lights, not the dimmer switch.
 
66HertzClone said:
I don't think the dimmer switch is at fault here. The actions you describe are exactly what the circuit breaker in the headlight switch is there to do. The headlight switch circuit breaker is shutting down the lights, not the dimmer switch.


yep, the headlight switch is the problem here. you can replace it with the switch from a 69 stang, but relays are better overall.