That's not air conditioning, thats just the heater. This is simply a little radiator, like the one in front of the engine, but in a housing with air doors & a fan.

Check the following
1. That the engine is actually operating at the correct operating temperature.

2. That the coolant control valve is working properly. This controls the amount of hot coolant from the engine that passes through the heater, & therefore controls the temperature of the air in the cabin.

3. That the core of the heater is not blocked. Try gently back flushing it. Disconect the heater hose where it connects near the front of the engine & hold a garden hose against it. Do not give it a full blast untill you have established that water is passing through freely & even then, take it easy.


If the core is really blocked you have several choices.
1. Remove the heater, then take out the core & have a radiator specialist clean or replace it for you. It will work a treat then.

2. Replace the whole heater with another second hand assembly & hope for the best.