Tail lights not working

Hello, new to this site and pulling out my hair. My sons 89' Blazer has an elec gremlin. The tail llights quit working. The turn signals and brake lights work fine, headlights also. Just the tail lights and front markers are out. I checked the fuse and sure enough, blown. The t/l 20 amp fuse was replaced and the tail lights came on but very dim then blows fuse after a few seconds. Now they wont come on at all, and fuse blows when I start car.....Any help would be much appreciated. I have been searching for a short/broken, bare wire under the dash and along the wire harness but found nothing. Could this be an ignition switch? The key will pull out with the car running, it is that worn...

Ready tp push this thing off a cliff or wire up some trailer lights and screw them to the tailgate.....Thanks in advance for the help!!

the first thing to check is the grounds on both lights, and then work your way towards the front of the truck looking for a bare wire everywhere. Pay a lot of attention to wherever there is a conection of any form.

Wire problems aren't usually hard, but the moment that you become frusterated take a brake, or quit working on it for the day.

Oh you might want to look for a bad bulb first. I had 1 car with a bulb that looked good, but sure caused me a big headach

ok sounds weird if its never happend b4, does it have a trailer light jack on it? if so check those wires, they went out on my 91 1500 and killed my tail lights, but the breaks and blinkers worked... also check the bulbs

Thanks for the speedy reply's guys ! I'll have checked the grounds at the bulb sockets and the light bulbs check ok as well. I will keep on looking for a short in the wires. There was some water under the carpet from a leaky roof rack (lots of rain recently). Maybe this got into the wire somehow....Thanks again

check about a foot away from the tail of the truck on the drivers side frame rail. there should be a ground there. check to see if any of the wires near that specific ground are bad.