I hope I'm not the only one this has ever happened to. I've looked around this forum and haven't seen it. I have a 2000 Blazer with a left rear tail(running) light out. Replaced both bulbs, not it. Fuse for it is good, has voltage thru it. Was actually able to energize the circuit thru the trailer harness. So I'm trying to figure out where the circuit goes after the fuse block, but I don't have a detailed enough wiring diagram to tell me. I'm guessing it goes to a switch or other connecting point before it gets to the socket?? Any suggestions?? Thanx

 

Try wiggling the socket around, see if that makes it come on...

If not, trace the wires back as far as you can...

Is there any corrosion in the socket?

 

The sockets are fine, that was the first thing I checked. I can getvoltage to the circuit by other means like I said,and each light is individually fused, which helps, but I'm not sure where the circuit goes betweenthe fuse blockand the sockets, and thereinlies my broken connection. I looked at a Haynes manual, but the electrical diagrams seem very general, likely because the manual covers a span of model years

 

I'm wondering.....could it possibly have anything to do with the multifunction switch? From looking at the wiring diagrams I have, it looks like almost everything to do with the rear lights goes through it. And I understand there was a recall on the switch. I should be able to get this replaced for free, right?

 

I don't believe that 2000 was included in the recall... And typically, it isn't one light that goes out, but both of the lower brake lights.

I have had to clean the tail light sockets on my truck. I disassembled them and cleaned all of the parts. After cleaning, I reassembled the socket and kept it protected with a liberal application of dielectric grease. The problem has not resurfaced.

 

The 2000's were in the recall. Your blazer is probablyprobably doing what mine did, both the mulifunction switch went on mine and the whole wiring harness to the rear fried. Ilucked out and got it fixedjust 7 milesbefore the end of mywarranty. In your case (unless you have an extended warranty) your best bet is to just trace the wiring as best you can back to the source and repair the wiring or just get a new wiring harness. Kinda sux but thats ur best bet.

 

Thanks for the suggestions. I ended up taking it to my normal shop, and the problem ended up being a broken wire under the carpet on the driver's side. What a stupid place to run wires. Oh well, it's fixed!