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Quirky heater issue on Dodge Caravan...





SixshooterSam

Making Automobiles Great Again
#21
Hopefully the issue is with the actuator, and not with the door itself. On some Jeep Grand Cherokees that I've worked on of the same time period, the issue was the door spindle itself broke. You could turn it all day long and it wouldn't move the door. But you will know whether or not that is your issue when you remove the actuator and try to turn the spindle with your fingers, it should only turn maybe 1/8-1/4 turn at most in either direction, and should come to a hard stop on each end of movement. You should also hear the door move when doing so. Well, you'll hear the door thump to a stop in each direction if you are in fact moving the door. When the spindle breaks on the Jeeps, it is obvious when you turn it with your fingers as the spindle will just turn freely and have no hard stop in either direction.
 

Ronsmag

I'm a schizophrenic and so am I
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#22
Seems to be a problem on Chrysler 300's I had a friend that had the same car as I do, 2010, I said my A/C is messed up and he said oh! it's probably that Blend door thing, he said same thing happened to him
 

Fogie

Swimming Pool Monkey
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#23
Seems to be a problem on Chrysler 300's I had a friend that had the same car as I do, 2010, I said my A/C is messed up and he said oh! it's probably that Blend door thing, he said same thing happened to him
Raptor's started clicking in 6 months, dealer replaced it with an "improved" actuator. Titan work truck's is acting up presently...oh for the old, cable driven doors.😕
 

SixshooterSam

Making Automobiles Great Again
#24
Almost everything that uses electric servo motors for temperature/vent doors will have problems sooner or later. Some cars are worse than others, but all of the big three American automakers all suffer from it. It's stupid. At least design them so the actuators are easy to get to, damnit!
 

Ron_O

Life, Liberty, & the Pursuit of Happiness
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#25
Well it'd be nice if it was only the actuator, if I can even access it, but up here the weather's so cold over the winter that there won't be a time that I jump in the van that I won't need some heat. So if it's not the door spindle stripped out I can at least do a quick fix until the actuator ships in.

Now I guess I have another question regarding the actuator function itself. On the days when the system would opt to bless me with full function, the temp control worked perfectly. So I'd be driving and suddenly I'd have heat, and could control it with the twist of the temp knob. That tells me the actuator was doing its job when it decided to work. It seems if the spindle was stripped out, it may come on but wouldn't want to continue to work throughout the full temp range throughout the trip (hours or all day), that it would essentially be either on or off, assuming the flap got stuck on one end of the spectrum or the other.

Before I came here for advice, I was thinking I could hose out the switches with e-cleaner spray and that would allow the connection to work. So I guess my first question would be whether that blend flap actuator is triggered by the temp control knob or by turning on the fan. I'd have to trace the wires. The fan switch is what turns on the system itself. Turn the fan off and everything goes off. My initial analysis/speculation was that something in the fan switch wasn't triggering the system to activate, despite the fact that the fan itself was working at all speeds. There must be two wires coming off that switch, one to trigger the actuator and another to control fan speed. I was thinking I may be able to jump a hot wire to see if it activates.

All the directional functions move fine, so it'll blow defrost, floor, front panel, or a combo, so that means that blend door is working fine. The fan works fine on all speeds. The heat won't trigger on. Maybe I'll see if I can pull some of the front dash panels off to get a better look inside and underneath. Thanks @Harley for the diagrams BTW. Much appreciated.

If that fan switch was dirty, it would make sense that it only came on rarely, but when it was left on everything else would work fine. When you shut it off and then back on again, that sensitive connection wouldn't line up and the actuator never triggered. I can play with the switch forever and it won't trigger on. But one more thing is that even if I left the system on when shutting off the motor, if I left the temp control on the cool end it may not heat back up again when I started up the engine. I had to make sure I left the heat setting around half way before shutting the engine off.

It's just been very temperamental and for the most part worked if we didn't shut it off and just let it come on when we started the motor. It worked more than it didn't. But since we didn't drive it all that often it wasn't a problem. Not until fall hit and it started getting cold again did it become a true PITA, and now it's just not tolerable which is why I've opted to have a 'van day' to work on several things at once.

Any thoughts on that switch rather than the actuator? I suppose if I can access that actuator plug I can pull it and put my meter on it to see if there's any signal coming from the switch. I'll have a look tomorrow.

Thanks again for your thoughts. I hadn't given an auxiliary heater any thought but that may work through the winter since more often than not I'm the only one in the van. I can't imagine they'd throw a lot of heat. But it sounds like I can get this done without having to pull the entire dash, so maybe I'll make it to 400k miles after all!

Let me add that I can't say enough to express how impressed I've been with that 4 cylinder motor and transmission. I pull all kinds of stuff with it and it'll go anywhere. Lots of mountain driving and extended trips and we really do enjoy driving it. I figured Daimler-Benz added some quality when they had ownership and I was lucky enough to benefit from that slot in the build quality. Before buying it I was totally off ALL American products and pretty much stuck to Toyota and German products.
 
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SixshooterSam

Making Automobiles Great Again
#26
Your issue is not going to be wiring/electrical. Don't waste your time chasing ghosts or overthinking it. Tracing and testing wires will be a complete waste of time.

Did you perform the climate control test as detailed previously above?
 

Ron_O

Life, Liberty, & the Pursuit of Happiness
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#27
Did you perform the climate control test as detailed previously above?
I didn't do the tests because they're referring to functions my rig doesn't have. For example, no separate 'wash' button or 'intermittent' button or readout. The rear window wash function is part of the wiper switch itself. I just assumed that was for a different model or year.
 

Ron_O

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#28
UPDATE:

So I had to use the van for the first time since my original post about this heater issue. Needed to run up north to pick up my utility trailer and some tools and such. It was about 25* when I left home but I had no choice. It was going to be a cold trip.

I warmed the engine up before heading out but still no heater. So out of desperation I took my snow brush and used the hard plastic back side to hammer on the area where the blend door actuator should be located. I hadn't pulled the cosmetic panel off yet, just wanted to give it a shot.

Sure enough, the heater kicked on! It worked. I figure something was just stuck down there so gave it a shot. What I'm thinking now is that the actuator is probably working fine, but that the blend door itself is getting stuck where it seats, probably due to some kind of grime over the years. So I made it a point to leave the heater on for the entire trip, probably about eight hours of driving overall, and it worked flawlessly.

My assessment is that once the door is open, as long as the heat is on and blowing when the motor is turned off, that door will remain open and continue to allow heat once the engine is turned on again. If I turn the heat too low it'll close the door and may not open again on startup.

I have to make the same trip again this weekend so we'll see if it continues to work. I wouldn't have known to try this had it not been for your advice here, and I thank you for that. After the weekend I should have more time so may be able to pull the panel off to go a bit deeper inside.
 

SixshooterSam

Making Automobiles Great Again
#29
UPDATE:

So I had to use the van for the first time since my original post about this heater issue. Needed to run up north to pick up my utility trailer and some tools and such. It was about 25* when I left home but I had no choice. It was going to be a cold trip.

I warmed the engine up before heading out but still no heater. So out of desperation I took my snow brush and used the hard plastic back side to hammer on the area where the blend door actuator should be located. I hadn't pulled the cosmetic panel off yet, just wanted to give it a shot.

Sure enough, the heater kicked on! It worked. I figure something was just stuck down there so gave it a shot. What I'm thinking now is that the actuator is probably working fine, but that the blend door itself is getting stuck where it seats, probably due to some kind of grime over the years. So I made it a point to leave the heater on for the entire trip, probably about eight hours of driving overall, and it worked flawlessly.

My assessment is that once the door is open, as long as the heat is on and blowing when the motor is turned off, that door will remain open and continue to allow heat once the engine is turned on again. If I turn the heat too low it'll close the door and may not open again on startup.

I have to make the same trip again this weekend so we'll see if it continues to work. I wouldn't have known to try this had it not been for your advice here, and I thank you for that. After the weekend I should have more time so may be able to pull the panel off to go a bit deeper inside.
Actually, many of these stupid Chrysler products of this generation reset the vent door positions when you shut it off, so odds are it will go cold again next time you drive it. My 300 does that and I have never understood why. The vents should stay in the position you leave them like most cars do.
 

Ron_O

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#30
Actually, many of these stupid Chrysler products of this generation reset the vent door positions when you shut it off, so odds are it will go cold again next time you drive it. My 300 does that and I have never understood why. The vents should stay in the position you leave them like most cars do.
I dunno, maybe it's been doing that but just re-opening when I start it up again, but I likely shut it down 10 times on this last trip and it worked every time I started it back up, even after overnight shut-offs. Maybe it's SUPPOSED TO BE closing but it's just too sticky to close back up once shut down.

Fingers crossed on whether it'll fire up again after several days of being idle. Either way it seems this settles the issue, meaning it's either a weak actuator or sticky blend flap. LOL maybe just banging on it for a while will eventually free it up again...
 

SixshooterSam

Making Automobiles Great Again
#31
I dunno, maybe it's been doing that but just re-opening when I start it up again, but I likely shut it down 10 times on this last trip and it worked every time I started it back up, even after overnight shut-offs. Maybe it's SUPPOSED TO BE closing but it's just too sticky to close back up once shut down.

Fingers crossed on whether it'll fire up again after several days of being idle. Either way it seems this settles the issue, meaning it's either a weak actuator or sticky blend flap. LOL maybe just banging on it for a while will eventually free it up again...
My money is on the spindle being broken. The actuators never work intermittently in my experience, they either work or they don't. Never seen a sticky flap, but certainly possible. But the spindles are plastic and break. Known issue.
 

Ronsmag

I'm a schizophrenic and so am I
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#32
When mine started screwing up first thing I noticed was fumes and not from my car then the clicking started then the heat came even when it was on A/C and the heat was blowing even when everything was shut off, then I would start the car and it would be fine but I would get loud clicking I was driving UBER and it was so loud I wouldn't drive like that, it would make the noise every 10 -20 minutes. That's when I took it to be repaired and the (a**hole)s only fixed 2 of the actuators then winter comes and I had to get the other 2 fixed by someone else