I have a 1993 Explorer and have had a problem with little or no heat and a fluctuating temperature gauge. The gauge will go up to the "N" in "Normal" and then drop back down. I get a lttle heat but not much and up here in northern NY that is not a good thing (especially when it is -40!). Any suggestions? I have had 2 different thermostats put in and a new radiator. Any help is appreciated.

 

I had a similiar problem on my 92. Feel the heater core hoses near the firewall where they go into the core. If they are cold, and your engine is warm then you probably have a blocked core. You can try and backflush the core(without removal), or remove it and either turn it upside down and flush, or replace it. It's an easy job and a new one is only about $20.

Mike