2004 Chevy Trailblazer Low Beam Headlights

[Susan]

We are having the same problem ...no low beams even after replacing the bulbs. Tried switching the HDM... did as described on your site and now the car has no power. switched back ...still no power. Help! I need my car..now it won't even start! Susan

[ProTech]

Ok, switching around the HDM relay should NOT cause any problems. You must have done something wrong, popped other fuses, or fried a module somewhere. But, back to the headlamp problem, you should remove the bulbs and check the connectors (sockets) for any burned terminals. That is a common issue as well. If it's not that, you're in the same boat as the other guy here and either have a wiring issue, bad headlamp switch, etc. Any of that would take some involved checking and diagnosis.