I had a similar problem with my 1998 espace which i thought was a heater matrix fault. After i had removed my dash it turned out that my heater pipes that carry warm air from the matrix had come off!! i just secured them on with cable ties and it was solved.
Saying that though that is the only time my car has provided me with a cheap fix!!
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.