check where your main wiring harness comes from the under hood fuse box and follow it through to the firewall where the main connector is.could be a bad wire at that connection.i have come across wiring problems right at the main fire wall connector for the main harness.some thing else to check.just a thought.

 

Today, while making a left turn, it all came back for a few seconds. I now have heat. But I'm about done putting up with it. It's 17 years old and I can't afford to fix phenomenal electrical issues any more.

 

Check @ the battery where the positive (red) cable attaches. You should find two cables, one to the starter, one to power box. At the end of the cable that attaches to the battery, you will find the fuseable link
David g. good luck

 

Already addressed.