Originally Posted by
NovalutionGSi
I can think of a few things here.
1, do you have the centre vents open? If you do they are straight from the blower motor and the outside... the ones that will have heat will be the side vents.
2, heater matrix blocked up? Had this on my GSi, gradually got colder and colder. So dropped off the pipes to the matrix in the engine bay, hooked up a hose pipe on both sides and then turned the tap on... nothing came out.... turned the tap up slightly and out came a load of gunk... after that flushed it through, connected it back to the car, filled up the water and had better heat out of it!