Hello
I have a friend that has a 1997 Grand Caravan 3.3, the problem is that the heater is not working and the blower only works by the windshield (defrost). I think is a control problem or a stuck door on the system, does anybody have an idea how to fix this problem.

Try a system calibration. Here's how:"Turn the blower on high. Simultaneously push the top and bottom wiper buttons on the left side of the climate control panel for 5 seconds. All the lights on the panel will light up. Then two lights on the left side will alternately flash for about two minutes and you'll hear the ventilation modes cycle. When just the top light on the left side slowly flashes push that button and you're done. All lights should be out and you should be back to normal. This is the climate control calibration/test and it resets the climate system computer/module." You’re A/C system must be working for this to pass otherwise the A/C lights will flash intil the A/C system is repaired.

Thank you I will try that tomorrow and will let you know.

Not that I know all too much, but seems I've heard folks saying a vacuum hose leak can also cause problems with A/C

And isn't there some type of A/C relay or resistor that might be faulty?

I did the SYSTEM CALIBRATION and now works perfect

THANK YOU

Thanks for passing on the good news. The HVAC calibration in one of a small group of easy fixes for an irritating problem on these vans.