Hey there i have a 05 chevy blazer and i just replaced my thermostat today, well i noticed my daytime running lights turned off and then up the road they came back on. When i try to engage high beams the indicator flicks on then off and no light comes out. Then randomly ill start it up and they are back on. Im lost at whats going on. I checked the fuses and they seem fine and the bulbs arent burnt out. Help!!

 

The headlamp circuit is complicated so we need to isolate the problem:

Power, grounds, wiring
Headlamp relay
Headlamp switch
BCM
Multifunction switch
Class 2 serial data

What happens when you put the headlight switch in the manual always on position? Are the headlights still intermittent?


George