Headlights blink irregularly

[Topsterguy]

I noticed last night that on my 69 Dart when I had the headlights on ( a rarity) that after a short time they started flashing on and off erratically. Ideas?  Thanks!

[wayne petty]

check for shorts to ground at the dimmer switch on the floor..  the wiring to the dimmer switch...  the wiring to the headlights..

the head light switch contains a circuit breaker just for the headlights as per DOT regs..

dirty worn contacts on the breaker arm can cause excessive heat and the headlights to cycle..  no easy way unless they are UNavailable.. to really get in and clean the contacts..

[38HAULR]

The inbuilt circuit breaker would be my suspect unless you have any obvious poor connections like  poor grounding.   I had an issue with one of these in a 1958 Holden .[  Aussie GM  product]  The lights would also mainly flicker on/off on a bumpy  road .   Simply replaced the switch assembly after removal and finding the contacts playing up .  These things must fatigue over time .  Back in the 90,s I purchased a 46 Mercury fitted with a small block Ford . This vehicle had been "professionally wired"     .    It would occasionally simply cut out unexpectedly ,pretty scary on a freeway ,requiring flick to neutral and re start . Sometimes simply sitting at traffic lights  The vehicle was fitted with circuit breakers and stupidly the ignition system was wired through the breaker that served the air con as I later found after the following procedure that led me to it.
It took ages to track  this stupidity down .Looking for a fault I ended up disconnecting the coil and loading the ignition system with one headlamp then adding more to try and force a fault . The lamp would extinguish then reset ,this led me to a fatigued breaker
I re wired the ignition and replaced what was a fatigued breaker .Given the thermal nature of these things it is understandable that they can fatigue. I suspect   in headlight switches where an older vehicle may have been upgraded in lights to Halogen .

Frank.

[Topsterguy]

Thanks guys! As always I knew someone would have answers here!   Larry