First off, thanks everyone for all the info in this site and sorry it is long. Want to give as much info as possible for the history. This site is my main source when tackling a problem. I have a 97 Blazer. The issues has started 6 years ago when I first got the blazer. The history is the previous owner put a aftermarket radio in, hot wired it directly to the battery. I saw a blown fuse and replaced it. AS soon as I did, I had smoke coming out from the defrost and under the hood. I saw the wire and pulled it from the battery. I spliced in a new connection behind the radio and everything seemed fine. Not long after, I had to splice in a turn switch as the guy broke the hazard button putting the radio in and just taped it down. The switch that was given to me had the wires already cut half way down the steering column. Within a short time, months or so, dont remember, the fuel gauge stopped working. I always kept it full so not an issue and just lived with it. Fast forward last fall, I turned the heater on high and saw smoke come from the speed control switch. I shut the heater off, again, smoked stopped. looking into it, the switch needed to be replaced. after replacing, everything again seemed fine. Wiring seemed fine, just a melted switch. Through this summer everything again seemed fine except every blue moon when I had the headlights on, the running lamps would come on for a second and then go off. Did this 2-3 times over a week or so and then stopped. Now a couple months later, I went out and would not go out of park. I found a blown fuse and replaced it. The next day, it blew again. Replaced it and still good. The next day after that, I noticed my dash lights was off, Check fuses and that was blown. I put a new one in, immediately it blew. I then put a 25a in and it held. Left the lights off as the sun was now rising. That afternoon when I got home, I turned the lights back on, started to smell something burning and pulled the switch out. I noticed the plug is burned and melted wires. checking over other fuses, The fuse for the brake lights was blown. Now I was wondering if there is a gremlin hibernating all these years from the aftermarket radio. I pulled the whole dash out and looked every wire over. Didnt see anything out of the norm beside the headlight switch plug and wires. I finally found my trailer harness was chaffed and hitting the body. I set the dash into place and connected everything, But if I turn my turn signal on, the fuel gauge moves with the blinker. I am to a point that I would like to replace the whole dash and harness since it is out right now. I found a guy right out of town that has a 96 blazer. The dash looks the exact same. As I was taking panels off, I noticed the 96 blazer seems a little different on the passenger side as the connections go. Not sure as I only have the under dash panels removed. Before I continue to tear this out, Is the dash and harness interchangeable between 96 & 97. The only harness I would look at is the one attached to the dash, not the one against the fire wall. Otherwise is there somewhere else that I am missing. I have never been good at reading wiring schematics as I have tried all weekend to make sense of them. Any and all help would be appreciated. Thanks

 

I have the same issue with the fuel gauge twitching with the turn signals. I have been told it is common and is possibly a ground.

 

if I can figure out that one plug, what it goes to, what wires I may need to add, so on to make the whole harness work, I will let you know if it takes care of the fuel gauge/turn signal issue.

 

comparing the fuse panel on the 96vs97, it seem the 97 has more options tied into the fuse box then the 96, it also has several spots that would be reveresed. example slot 12 and 18. one year is empty, the other year its used and vice versa. has anyone out there ever attempted this swap or if I start, will I be in nothing but a nightmare ending up getting another harness out of the junk yard for the correct year?