I have an 87 Cutlass Supreme that is my every morning delivery car. It is cosmetically challenged but starts every day and rarely lets me down.
Recently a problem has developed with all of the headlights going dark after only 2-3 mins on High Beam. When I click back to Low Beam they come back on. It's as if a circuit breaker was tripping and auto resetting. I have owned the car for many years and this is a new issue. The quad rectangular sealed beam headlamps burn out often as I use them 2-3 hours every night. I have replaced the headlight switch, but no help. The dimmer sw was replaced abouy 2 years ago as it was not reliably switching back and forth.
Any ideas would be appreciated.

Bob
normalones@juno.com

 

Ok, update time.
Today I started to change the dimmer switch. When we removed the old one and unplugged the electrical connector, one of the terminals on the switch and the corresponding slot in the pigtail were both burned and melted looking. Had to order the new pigtail as nobody keeps it in stock.
Could this have been the cause of my high beams failing after just a few mins ?

 

That was definitely your problem.

 

Thanks for the input. New parts arriving Tuesday. I will be glad to have this fixed.

Bob