As it says. The internal temperature can be set to any temperature when the AC is on but doesn't get hot when using heater only?

 

Greetings Rob - Just to be clear, if you get the temp all the way up to 'HI' with the AC on, you get heat, but if you switch the AC off, no heat even when still on 'HI' ? (just suggesting 'HI' to ensure heat is engaged regardless ambient temp).

 

Odd as it may seem but the heat actually stays on when you switch off the ac. When started from cold it just doesn't get hot.

 

Odd indeed. Is this something new? Where I am trying to get at is if you have seen a degradation, overtime, of the heat 'temperature' (i.e. became lukewarm as opposed to HOT air when on highest heat). A clogged heater core and/or a failing secondary pump is such a common issue on this car that maybe it's just that the problem - even though the symptoms you have don't really align.