1997 sable gs no heat
 

My 97 sable has no heat, just fairly warm.
2 months ago took to shop to get fixed, new thermostat, new anti-fluid, heat is ok again.

Yesterday was on expressway when i had to punch it down to pass a truck~~~~ blower motor shut off... Left off gas pedal an blower came back on. With just warm heat if that.
Back to shop and cant find the problem, can anyone please help me here? :(

I don't have a Sable, but I would feel the heater hoses going into & out of the heater core to if they both are hot. The return hose would be slightly cooler. If you getting hot water to the heater core, then that should be ok since it was putting out plenty of heat previously. If they are not hot, then I would look for a control valve which is usually in line with the inlet heater hose. Not all cars have this valve.

Then I would look for a temperature blend door which blends cold & hot air to get the desire temperature. I suspect it is stuck or has bad actuator which is usually vacuum operated. It would be a rupture diaphragm or vacuum hose.

You might also check for a bad vacuum hose in the engine compartment leading into the firewall.

Yesterday was on expressway when i had to punch it down to pass a truck~~~~ blower motor shut off... Left off gas pedal an blower came back on. With just warm heat if that.

I still got no heat