No heat inside and overheating

Hi,
When you say " œdoesn't work' do you mean there's no air coming out or there is air but it's not warm?
If no air at all: check fan fuse, relay and motor.
If you have air but it's not warm, check coolant level and thermostat.

Is the coolant level full? Did the temp gauge do the same thing with the old thermostat?

As far as the heat in the car, there is only one heater core that provides heat for both sides of the car. If one side is getting heat, then the other should unless there is a vacuum leak to one of the vent doors that directs heat / air flow to the different vents. Therefore, it is my opinion that since you get heat on one side, there must be a vacuum leak to one of the vent doors. Check under the dash for leaks or even linkage that actuate the doors that may have come disconnected. Also, with the engine running, you may get lucky and hear a hissing sound from where the leak is coming from.

Let me know what you find.

Joe

Try replacing the thermostat and make sure the coolant level is correct and go from there

The first thing you need to check is if both heater hoses going to the heater core are getting really hot. Let me know what you find.

Verify that the thermostat is not stuck open or missing. Most likely you need to have the system bled, it is very common for this car to develop air pockets in the cooling system after it's been apart. IT'S EASY ENOUGH TO DO BUT YOU NEED A SPECIAL FUNNEL OR A VACUM FILLER.

Bad connection somewhere behind the dash or a possible bad blower motor. You need a shop to at least diag it for you to confirm

Roy

Motor is more likely.

Roy

Check fuse and relay under hood fuse box first. Then see if resistor or blower are getting power or not. If no power to blower after relay/fuse check have a local pro scan for problems with control head.