i have 2005 silverado 1500 i just noticed today driving home that my headlights and dome light were flickering slightly. the truck has 155,000 miles and it was 80-85 degrees out tonight. any ideas?

 

Maybe a loose power or ground wire. Do they flicker when you're stopped (no vibration)?

 

no they flicker both while driving and parked. im completely lost on this one since i replaced the alternator a month ago

 

They probably don't flicker when the engine is off.......Alternator off, lights on battery. You may still have a bad alternator. There should be a way to test this. It may take more test equipment that you have access to. Check with a parts house to see if they can test your alternator for you.