Mine has done this since almost the beginning. But it my case, I try to close it manually and it will not budge. I have to hit the buttons on the fob again and it will reset it. Then I can close it manually with ease.

 

Thanks I will see if that works for me. I still would like to fix it!
Dan

 

You might try new struts for the rear hatch. When ours got stuck open, it kept intermittently doing it until I put in new lift struts, then the problem was solved. I think if the struts are weak, it tends to bind up a little when opened by power.

 

Has anyone had a limit micro switch be an issue, my problem seems electrical? Any PDF's available to diagram the power mechanism and trim that needs removing?
Thanks
Dan

 

I got new struts but that didn't fix it, still no power close Removed neg battery cable,not fixed but I can manually close the tailgate now before it was just locked open.

Any ideas why it won't close under power?
Thanks
Dan

 

I don't know how to determine if it's the problem or not, but if you do find the actuator module is the problem, I have a spare for sale.

 

Wiring diagram appears to be available here:
http://www-5.dodge.com/bodybuilder/2007/rswdz.zip
It's under the "power door locks" section, called "power liftgate module", starting on page 8W-61-17. Looks like there are several switches inside the power liftgate motor that are fed as inputs to the power liftgate module. And also a bunch more switches/sensors from the cinch/release motor also fed as inputs to the power liftgate module. But then the power liftgate module is connected to the front control module via PCI bus, and also connected to the body control module. Lots of things happening there - certainly more complex than I would have thought!

I do notice there is a "clutch" in the power liftgate motor that is activated by the power liftgate module, so that might explain why it seems like it is not possible to push it down manually sometimes. My 2007 GC has had the problem where I cannot manually push the liftgate down until I push the liftgate button on the fob, which seems to reset something (while making a clunk) after which point I can close it normally again.

I also found a post here which describes some of the theory of operation:
https://dodgeforum.com/forum/dodge-caravan/353852-05-sxt-rear-hatch-opens-but-will-not-close.html

 

I swapped in a complete motor drive unit and it does the same thing, goes up under power but will not come down.

I also got the lift gate computer module and swapped it in, same result.

Seems like my originals are OK or both these have the same problem?
Dan

 

So that leaves only a few components that could still be a problem (assuming it's unlikely that both sets of parts you tried would be bad):

Pinch sensor (this is supposed to prevent the liftgate from closing on a person) - I could see this preventing the power liftgate module from initiating a "close" action. There might be a way to temporarily bypass this for testing? This is an input to the power liftgate module. There are two in series. I'm unsure which state (short vs high resistance) means "no pinch detected".
Liftgate cinch/release motor - has a "liftgate pawl switch" that is an input to the power liftgate module. Perhaps it might not close if the pawl switch is not in the right position?
Body Control Module - seems less likely to me, but it is connected to the power liftgate module. Unsure if it is just reporting status from the power liftgate module or actually driving a signal into it.

 

Here is a description (albeit from the 5th gen) of how the pinch sensor is supposed to work:

https://www.torquenews.com/106/chrysler-recalls-2012-minivans-rear-liftgate-pinch-risk

"When the rear gate of the 2012 Chrysler T&C and the Dodge Grand Caravan are closing, these sensors monitor the amount of pressure pushing back against the electronic closing mechanism. The back pressure should never exceed the target amount and when it does, the sensor tells the rear gate to stop closing and swing back open. This way, if there is anything like a child’s hand or finger…or a dog’s tail…the door knows not to crush the object that is preventing it from closing."

 

I think the 07 is the same however I can not test it as the lift gate won't begin to close with power.

I did test it opening and it does stop opening.
Dan

 

An owner of a 2002 caravan reports a resistance of 10K when no pinch is detected, and a resistance of close to 0 ohms (short) when a pinch condition is detected.
https://www.justanswer.com/dodge/7vhxr-dodge-caravan-2002-power-rear-liftgate.html

It also sounds like a DRBIII would be very helpful for diagnosing (not to say that you can't figure it out otherwise though) as it could instantly give you all the sensor/switch readings.
"The power liftgate system was designed to be diagnosed with an appropriate diagnostic scan tool, such as the DRB III®. The most reliable, efficient, and accurate means to diagnose the power liftgate system requires the use of a DRB III® scan tool and the proper Body Diagnostic Procedures manual. The DRB III® can be used to observe various switch statuses throughout the power liftgate system to help the technician diagnose a defective switch or component. The DRB III® can also be used to actuate various components throughout the power liftgate system to help the technician diagnose a defective component."

For a 2009, but maybe still pertinent:
ftp://oskin.ru/pub/chrysler-dodge/m.../manuals/Service Manuals/2008-2009_RT_Town&Country_Caravan_Voyager/liftgate.pdf

"If a liftgate pinch sensor is activated during a power close, the liftgate will reverse direction. If a pinch
sensor is already active the power liftgate will not initiate a power close. A pinch activation during latch
cinch will stop the cinch operation."

"Pinch sensor reads 10K ohms when not pinched. When pinched, shorts out the 10K ohm resistor and should read from 0 to approximately 200 ohms."

"DRIVE CLUTCH Provides + 12 V to clutch in power liftgate drive unit to engage drive mechanism for power open or close"

So maybe you can check voltage on the drive clutch to see if the motor clutch is active and preventing you from manually lowering it? That might provide a clue as well.

 

Thanks for all the help, it turns out one pinch sensor is missing and the other is unplugged. So I guess I just found the problem!

 

Yes all it took was a $5 pinch sensor from the bone yard and it's working fine.

Thanks again
Dan