i have a 96 blazer 4.3l v-6 w/95,000 and lately when the car gets warm and the dash starts to heat up the headlights and dash lights go on and off completely and when you bump the dash it does it on command but it is only after the truck has been running for a while, also the daytime running lights no longer work either.if anyone can help i have been to my local mechanic and he can't figure it out.please let me know.

My exact blazer does the same thing did you ever get it fixed

Sounds like the headlamp switch might be overheating. Possibly a bad switch.

I would agree with ricksza

Open glove compartment -> pull off back panel -> pull out far right relay bend over 87 pin, not the 87a pin. This will disable the (daytime running lights) DRL diode module. This will atleast help you isolate the problem before spending money on parts to replace.

Frank

Ok, after replacing both headlamps, disabling DRL module, replacing Dash Switch and High beam/cruise control switch. I FOUND THE SOLUTION! There is a second wire coming off the battery terminal. Mine was complete worn out and had a bare spot. I cut off the worn part and reconnected it with a new splice. My headlights haven't flashed on and off since.

glad you fixed the problem but this thread is 3 1/2 years old. please refrain from posting in old threads.