If there is no heat in a 1996 GMC Jimmy what might be the problem?

Answer 1

Answer

I'd start with thermostat and heater core

Answer

"You have no heat" is a pretty ambiguous question. There could be a lot of things going on. The first answer is a good one, try the thermostat. While you're at it, I would also suggest flushing the cooling system. You have to drain the system to take care of the thermostat anyway. Buy some cooling system flush, and have at it. When you refill the system, be sure to use a 50% - 70% mix of Dex coolant to water.

If that doesn't work, you may want to try the heater core. This is a big hassle, as the heater core is buried below the dash - which means you have to pull the dash out. The jobisn't hard, but it is a pain in the rump and time consuming.

On the other hand, if the problem that the blower isn't blowing, you're into a whole different issue. My 96 Jimmy's blower turns on an off seemingly at will. The warmer it is outside the more likely it is to work, which is a huge drag. My heater core went bad, so I changed that, as well as the thermostat, and heater controle module. Still no good. This leads me to the conclusion that there is either a loose connection in the wiring harness, or a problem with the blower itself. I think that it's the wiring because if I whack the dashboard, the blower will sometimes turn on.

Before starting any project, get a good manual (I use Haynes) and read it thoroughly. You will be glad you did, and the book will more than pay for itself in no time!

Good luck. -- Mr. Dog