A factory harness is all fused they shouldn't burn up like that unless someone put a bigger fuse than called for or there is an unfused wire running straight from the battery for an amp or something. you have to figure out exactly what started the burn in the first place or you will get it all wired up and it will just happen again. Your temp guage wire is grounded out somewhere thats why it pegging the guage so there are still wires touching each other somewhere inside the harness. Its not an easy job to do most mechanics wont even touch a job like this the only way to do it right is to pull the complete chassis harness off of a donor rig which is a good full day at a wrecking yard bring it home and pull all the interior out of your runner and start plugging the new one in as you pull your bad one. the way that your fixing it is kind of just a bandaid.
