Hi,

I've been struggling with this problem for days, of my headlights not working (2001 Blazer). I replaced all the bulbs, checked fuses, swapped relays, cleaned grounds, checked voltages and continuity all over the place, even took it to the dealer and paid them $30 to look at it - every consensus was the multifunction switch on the column.

However, after even more beating my head against the wall, and working on it till 4am today, I took it for a test drive - the lights seemed to be working now, after I cleaned and tightened four grounds on the radiator support, but every bump I went over, I'd hear a click and they'd turn off. If I even opened the door and slammed it, they'd turn back on. It would click many times very fast, and was very annoying. ;-)

So I tore a couple pieces of dash cover back off, and noticed the clicking is distinctly coming from what I'm calling the "under dash fuse relay box". I don't know if that's it's technical name, but that's the best I can describe it. It's the black box between the steering column base and the parking brake, with about a bajillion wires going into it. Every time this box clicks, the headlights go off. It even clicks with the car off and key out. ???

So, where do I find more info on this box? What is it, and how do I replace it? If I take it off, are there relays inside it? Google is not being my friend right now, and I can't find any proper info on what this box is. Any information would be helpful, thanks!!