need help with my truck

[87_GT]

i got a 88 gmc 1500 pickup and it has like a digital heater control on it. last week after about 5 minutes of driving it blew the fuse on it, so i put a new one in and it blew instantly. so i was thinking it was a short some where, so i started taking off some of the dash and moving the main heater control wires around trying to just see if i can move it off the spot where it is shorting. well after i moved all of the wires around i stuck a new fuse in there and the heater controls worked, but after about 30 seconds there was a ton of smoke coming from the dash and a bad burning smell, but the fuse would not burn out. i am really just looking for a quick fix here guys it is only my $500 winter beater, so any and all advice would be helpful.
thanks,
steve

 

[87_GT]

well i found two wires that were completley melted and burnt, now my question is how do i know what started this? i mean if i just splice 2 new wires in there how do i know that the same thing won't happen. i really know nothing about wiring so any info is appreciated

 

[HISSIN50]

You're right - you dont know that it won't happen again. I might try and bench test the blower motor with a FUSED jumper to see if the motor is resistive/seizing. That can cause an excessive draw that blows the fuse or melts wire in lieu of the fuse blowing.

Obviously use wire of the same AWG or numerically smaller (actually bigger) wire for your splices.

Good luck.

 

[BlownFiveLiter]

I seem to recall my dad having a similar issue with his old 89 Chevy truck. I don't know exactly what happened since it was at least 10 years ago, but I'm pretty sure they replaced the module itself.

 

[87_GT]

hey thanks for the help guys. i ended up just cutting the two burnt wires out and my blower motor works with out them, so i am just going to drive the truck like that. it is only my $500 winter truck so i am not too concerned if other stuff isn't working properly.