When i initially start the car(1989 Mustang 5.0l LX) it fires up fine runs fine etc, i shut it off and then try to start it up again( after a 10-20 min drive).I get a slow crank over and the small wire on the negative side( at battery terminal to inner fender ground) gets very hot -begins to smoke and car wont start.Most of the time the fuse for the instrument cluster(15 amp) blows and i lose all response/power for instrument cluster guages.I had the dash apart to change the heater core it was after that the problem started.I noticed the pigtails going into the back of the plug for the headlight switch slip out.I have pushed them back in and tightly wrapped tape around the wires to hold them in place.After the car sits for a while 5-10 mins it will fire back up again just fine and if i turn it off same thing again it wont start -wire smokes.Is this a ground problem with that smaller wire off neg terminal, is it the headlight switch/plug, a pinched wire behind the dash related to the instrument cluster or possibly something else.
The heavy main battery ground is bolted to the bottom right side of the engine block and seems to be properly secured.
The heavy main battery ground is bolted to the bottom right side of the engine block and seems to be properly secured.