intermittent inop headlights

[mr.belvedere]

hopefully someone has been down this road and can give me a little guidance.
67 gtx, headlights will flicker after about 20 minutes of operation, and will eventually just fail after about 2 minutes of that. the car did this 18 years ago when i first got it, so i replaced the h/lamp switch and the connector because it was melted. no problems after that, but now years later after the resto, happening again.

new h/lp switch
good dash harness from donor car
new dimmer swich
good dimmer connector(not melted)
check of dash harness(nothing melted/no broken wires)
check of forward lamp harness(nothing melted/no broken wires)

all other lamps function perfectly. directionals, hazards, brake lamps, etc. and they all work as they should when used in combination. lamps are are very bright, and grounds are all good (i'm a fanatic about clean, solid grounds). not sure if the tailights are going out at the same time or not, and i dont remember if my dash lights went out with the headlamps, i was concentrating more on getting home in one piece. no blown fuses either. anyone know if there is a circuit breaker in the switch?

very frustrated. possibly another bad h/lamp switch? looking for my wiring diagram, but i am open and very appreciative to suggestions.:confused:

 

[Elvad]

Check this...

I had four Chargers that all did this in the same place. Check the wiring to the lights where it passes through the radiator support on the driver side. The sheetmetal is very sharp and easily cuts through the insulation shorting to ground and melting the Hi beam switch.

 

[HEMI-ITIS]

Also look close at the bulkhead connections on BOTH sides.

 

[beezee]

Sounds like a good time to upgrade to relay,s . Locate them under the battery tray and tap into the headlight harness . This will take all the current your light,s draw off your harness ,switches, etc. Less problems and brighter lights.

 

[beezee]

Here,s a link
http://www.moparts.org/Tech/Archive/elec/10.html

 

[mr.belvedere]

thanks for the replies. all connections are in good shape, and were put together with a good dose of military issue dielectric grease during reassembly. now its time to start unwrapping harnesses to check things out.
i was unable to duplicate the problem in the driveway in broad daylight (of course!). i geuss while i'm in there, i should upgrade to the relay setup,i thought about it before, but now i really have a good reason.

 

[Redpolara]

I had the same problem, it was the headlight switch and the dipper switch.
You could try hitting the dipper switch a few times with the lights on,to see if it has any effect on the situation