Heater problems '86 TC

I recently purchased a very nice 86 town car. Only mechanical problem is the heat. It never gets hot just sort of luke warm. Living in Florida not a huge problem but a pain in the mornings sometime when trying to clear windows etc. The heater fan blows and fan speed control and all directors (defrost - floor etc.) work correctly. The air blows ICE COLD. Does this sound like something as simple as a thermostat?

Sounds more like a bypassed heater core, or stuck coolant flow valve inline to the heater core.