About 3 months ago, one of my low beams went out, although after turning on the high beams, now all four headlights work. Of course if I turn the high beams off, then again, only the one low beam works. Anyhow, I just left the high beams on until I could tend to the problem. A bit after that (about 2-3 weeks) when I tried to turn the high beams off, as I had just left them in the high position, they would not switch back to low. So I just left that alone until I could get a chance to do something more with it. Now that was about a month ago and all this time, I have been driving with both high and low beams on. Well anyhow, while driving home tonight, my headlights went completely out and will not come back on. Although my parking lights, brake, lights, dome light, dash lights, etc... still work as normal. I checked the wires for the most part and couldn't see anything wrong and then looked at the fuses, and they looked fine. I don't believe I did anything bad to the switch, but when I turn it off and on, those other lights come on, just not the headlights. No low beams or high beams. So now I am lost and need to fix this ASAP! This is on a '85 K5 Blazer with a 6.2L Diesel. Is there anything I can check or do? I really need some help quickly on this! Thanks very much.

 

Were you working on something electrical prior to this? Could be a short, bad relay.. It's a pull **** right? Might to replace that. Contacts could be worn. See if you're getting V before and after the relay. Have headlights on of course.

 

You've definitely got a wiring problem somewhere. You probably blew the fuse due to the current draw.