Well I just posted another thread about my power loss problem here's another one thats been stalking me for a year.

When I turn my heater on (not cold but hot air) it will SOMETIMES (about 1 in 10 times) blow out hot air then it turns to cold and my temperature gauge drops down to zip. Usually I turn off the truck turn off the heater and turn it back on and I'm good to go. Ideas?

 

the only time a temp guage goes to zip and the heat gets hot for a few mins and then blows cold in conjunction with each other usually equals low or no coolant....


but that was in the old dayzzz


...zap!

 

Maybe the thermostat is going bad. Could be that it shuts for a second (no heat) and when you restart your truck it re-opens. Not too sure about this but on an old car I had I had this exact problem with my thermostat.

 

I just replaced my thermostat it had the same symptoms works great now hot air and all. For the $16 it will cost I would start there first