98 Grand Voyager Heater Blows Cold But Defroster Works!!!

Ok so this van has given us some really weird issues since we bought it. We have the AC/Heater Control panel issues so many of you have with the lights blinking and the dash dying etc. Figured it out just have to replace the part. The tranny issues, well we serviced the tranny and so far so good! The serpintine belt slips off in really rainy weather, runs hot etc.
Now the darned thing wants to quit blowing hot air as soon as we move up north from Florida!!!!! The really weird thing is, the defroster will blow hot sometimes. So there's some hot air in there somewhere just not getting out of the vents!!!
Any ideas???:banghead:

If I remember correctly the air blend door motor (not sure on that name) will fail to the defroster side as a safety feature. Have you tried a ventilation panel self test? Might reveal the problem. Could have a bad blend door motor or another bad panel.

I did the venitilation self test yesterday and when hubby took it to the store lo and behold it worked!! So I will update everyone after I drive it again if the heater is still working.
BTW, all of the lights on the ac/heater control panel were blinking prior to the self test and now they are not. Just FYI for everyone who has had or is having this problem.
Another thing.... I LOVE THIS FORUM!!! You guys have saved me mucho money once again!!!
Thanks everyone!

Flashing lights in the panel is an indication that the calibration test must be run . This can usually happen when you have a weak battery or the battery has been disconnected previously , running the test will get rid of the vblinking lights provided it doesn't find a problem while running the test , if they are out most likely your problem is fixed...

Well, drove the van today and the heater worked fine!! So guess the self test is what it needed.
When we bought the van the next day the dash quit working completely. I played around with things and found that the connector behind the ac/heater control panel had a burnt out pin and melted connector. So I wiggled it around and it came on. So now, we just bang on the dash if they go off. But the lights on the heater control panel have always blinked off and on, guess its a short in a wire somewhere, not sure. This van has a lot of electrical issues thats for sure.
The serpentine belt did come off a week or so ago in the rain, so maybe thats what made the self test necessary.
Whatever it was, its working now!

Yup, these vans are an electronics geeks dream. Plenty to fix. As for your belt slipping off there are posts on this forum about a kit you can buy that fixes the problem. They also recommend the Gator belt by Goodyear. Check it out. Glad to hear you're getting heat now. Cheers!

Thank you so much for the help!! :o)
I will check out the fix for the belt too!!

I'm impressed. How do you do the venitilation self test -- is there web info detailing it?

THANKS

stb100 http://www.allpar.com/fix/codes-climate.html

THANKS Rip. Had seen the Allpar.com page and I ran the calibration/diagnostic. At the end, only thing flashing is Rear Wiper LED, which is good. Ran cool down test too. All good I think.
During 1st test, psgr side blew hot air as test cycled thru. When done, cold only (!!). Repeated test, same outcome. Guessing psgr side will work if I can get it calibrated right but am stumped as to how. Does this sound right or does it sound like a physical repair's needed....

STB

That Allpar page is about the only thing on the net about the climate system test besides some scant info on this forum. Would love to find more detailed info on it. It's easy to assume it's a thorough test that tests everything but, based on experience working on jets, that can get you into trouble quickly.

Based on your test results it's safe to say the actuator, wiring to it and door linkage are good. What's still in doubt is if the switch command is getting to the actuator. Yes, it works when you do the test but, I'd bet that's from a predetermined command from the module in the panel and not from the switch on the panel. To prove that try getting to the connector at the actuator (probably easier said then done) and check for a varying voltage as you move the switch. If it's not there I would change the panel. You could try getting at the switch in the panel but, you could open a can of worms. When you get there a climate control panel from a junkyard would be your best bet or borrow one from a really good buddy with a 96-99 van. I'm sure new panels are pricey.

I recently had nothing but hot air coming out the rear bottom vent. Never shifted to cold out the top vents when the temp slider was cycled. Did the cal test and nothing happened in the back. Got to a connector under the right rear trim panel and found the slider switch was sending a voltage but, the actuator was dead. Changed the actuator and all is well. Redid the cal test and still nothing happened. Just shows that test isn't all it's cracked up to be.