lights flicker

[farmboy81]

I have an 81 Chevy k20 and I'm having an issue with my lights. Every thing turns on but after it's on for a few minutes they start to flash please help.

[Donut]

Just went through this, unfortunately I think I fixed it by b.s. luck.

Headlight switch?  There is a circuit breaker internally.  If overloaded it'll trip, after a little bit it'll "reset", giving you a flashing.
Verify all wiring is good and clean.  I had 1 ground broken in a factory splice.  Didn't see it until about 3rd trip in.  Also check dimmer switch.  Verify its working properly. 

I did a "relay mod" to take some of the electrical strain off the factory switch.  Factory pulls all juice through the headlight switch, now it's just enough to trip the relays and fire off the lights.  Lights are a little brighter now also.

BTW, welcome.

[farmboy81]

Thank you for the reply I just put In the second new switch with I luck iv ben told the switch itself grounds threw so I cleaned it and also ran one septate but how did you wire the relay ?