my 1993 civic heater doesnt work and its starting to get cold. the cold to hot switch wont go to hot and stay in hot position no matter what buttons i try it still doesnt heat i also have a noise on the drivers side when you turn the wheel sounds like clicking might me a cv axle? my other car did that and also i think the thermostat needs replaced because it runs a little warm on short trips but fine on long trips and its got new radiator and all that just got the car and they went through it all but apparently not hoping its nothing major its just my second car for backup

 

The first symptom of not having enough coolant is that the heater doesn't work. This may also be related to overheating the engine. With the engine cold, check in the radiator that it is full. Remove the radiator cap and check in the radiator itself, not just the white plastic tank.

The hot/cold control is purely mechanical. Moving the lever operates a push-pull cable that goes to a mechanism on the bottom of the heater box, which is visible under the dash above the "hump" in the center of the car. The mechanism moves a push rod to open and close the air to the heater door, and also operates another push-pull cable that goes through the firewall to operate the coolant valve to start and stop the flow of hot coolant through the core.

Look at the CV boots, if they are broken that lets dirt get into the joints thus they are probably shot.