I got a 1998 Blazer as a gift. When the previous owner bought it 11 years ago it had been returned to the dealer because the AC didn’t work. She took it to a few mechanics but never got it working.
She gave me the car about a year ago.
I’ve noticed that the AC actually does work intermittently but this spring I noticed that the heat stopped working.
My mechanic replaced the water pump and the thermostat and both times the heat started working for a little while and then stopped again. Recently I noticed that my coolant was almost gone and refiled it. This, however did not get my heat working again.
I’d appreciate any ideas.
There may be a problem with the vent doors that is causing the trouble with the AC and heat system.
You have to wonder what happened to the coolant and how it got so low. There may be a head gasket leak but hopefully there is just a loose hose clamp somewhere. Keep a good eye on the coolant level.
It sounds like you have a coolant leak, or at least that air is leaking into the cooling system. The trapped air prevents circulation in the heater core. Each time that work was done on the cooling system, they bled the air out, and that made it work again. I bet that if you bleed it again, it will work for a little while. Try it and see. If it does, then you need to find the leak and correct it. It may be a head gasket.