85 fiero gt heater problem

Just bought a 85 fiero gt for wife and after tunnup it runs great, so far. The only problem seems to be that the hearter doesnt put out much heat and barely defrost the windshield even after the car has come up to temp. Is this a common problem, are there any fixes?

I had one and that wasn't the case. Have you measured the temperature coming out of the windshield vents. Also you while check to see how much flow is actually coming out too. There are plenty of small things that could happen. Also is the heat from the front vents good? If so then there could be something clogging the vent to the windshield or it isn't totally opening. If not then you should check to see if there is anything ontop of the heater core. I found that i needed to pull my heater fan out then clean all the old leaves out. It helped a good amt. This was before it leaked and i had to replace it of course... Anywho get back to me and maybe i can help more.

Hey thanks for the info. I found the problem someone had put the thermostat in crocked and thins were not flowing like it should have. So I fixed that and the the heater core went bad. Everything is fixed and the heater is working great. Thanks for the info I appreciated the help.

Mike