Stalls when heater is on

It will run with no heat?

Maybe your A/C compressor is locked up?

Any heat setting with defrost included will make the A/C clutch engage onto the compressor (this aids in removing moisture from the windshield, older, non computer cars did not have this feature).

What I am trying to say is that as long as the A/C compressor is not engaged, the clutch pulley will freewheel (as it should).

If you can see the compressor pulley, have someone watch it while you start the vehicle up.

Watch close to what happens when the heat is turned on, was it an instant stop or did you see the belt slip?

Let's say the pulley suddenly stopped and you saw some slipping of the belt.

Most likely the compressor is shot/ but the pulley still works with no heat or A/C being used.

You have two choices for now:

1) Replace the compressor (might need it in the summer!).

2) Unplug the A/C clutch (it can no longer engage the compressor) no matter what heat setting you use or turning on the A/C, It will not engage the "broken" compressor.

You now have heat (any mode), vehicle will not stall out. You can survive a while longer!

This may not be your situation, it is a place to start.

Return here and let us know what you find!

The Medic