because heat core was removed?
pre-heat spark plug, if this works then replace it.
Have you checked to see if the elect. fan comes on ?
If it is leaking it needs replacing. If you have no heat and the inlet heater hose is hot and the outlet is cool, it is stopped up and may need replacing, if it cannot be flushed out.
In the center of the dash. It's the unit you select options on. It controls the AC and Heat.
The heater and the AC are different systems other than the blower, so they normally fail independently. The AC can fail for many reasons, high on the list are low freon (which means there's a leak) and the compressor.
It is possible that the outside temperature sensor is defective. As a result the heat only works at certain electronic temperature control settings.
In the Heat of the Night - 1988 Ches and the Grand Lady 7-16 was released on: USA: 26 January 1994
latent heat of mercury
It could be a couple of things, but check the easy things first. Check the anti freeze level with a anti freeze checker, if there us more water in the radiator than anti freeze the water will evaporate and the heater will blow cool. next check the thermostat, you have to take it out and heat it up in hot water and see if it opens up when it reaches the right temp when heated it will open up,those are usually the two most common problems.
On the 3.1 it is on the driver side, under the exhause manifold behind a heat shield. Not an easy get to it location.
Mercury is a good conductor of heat. Unfortunately, heat will produce vapor which is toxic.