I have a similar problem and found a thread about the gear on the blender door being worn out which sends s false signal to the hvac comp to shut off... Let me see if i can find the link to the thread...


Sent from my iPhone using JeepGarage

 

http://www.jeepgarage.org/showthread.php?t=83567

Check that out, it's a great post for this problem

Sent from my iPhone using JeepGarage

 

Passenger side Blend door gear replacement

Check that out, it's a great post for this problem

Sent from my iPhone using JeepGarage

I have an issue with my driver side temp not working. actuator motor and both gears are fine but what I did notice with the motor out and plugged in, when you adjust the temp for driver side only, the actuator motor just keeps rotating in one direction or the other so if that was actually back where it was supposed to be, it would jam the blend door to one extreme or the other and eventually break the gears or burn out the motor. could it be that I just need a new control panel? My blower motor also shuts off intermittently.

 

Been there, done that. Definately pointing a finger at a broken door gear. As for which one, check the output temperature on both sides. Set one side full hot and the other side full cold. Vise versa. That gremlin should be easy to find.

 

A few folks have mentioned this or similar problems. I thought I'd add my $0.02 worth...

Symptom:
A/C blower cycles on high speed for a minute or so then drops to zero or very low speed for half a minute or so. Then the cycle repeats. Typically the high - low blower cycling repeats 5-6 times over a period of 10-15 minutes then the cycling stops and the blower runs at an intermediate speed. This happens regardless of whether the A/C is set to Auto or a manual speed setting. Note that cold is still produced during this cycling. It appears that this is a blower only and not a compressor problem.

I brought the Jeep in for this A/C blower cycling problem in September 2016. It was determined that parts were required and they were ordered. I brought the Jeep back in on 3 August 2016 to have the parts replaced. Two parts were replaced at that time:
1. Module/resistor/power, blower motor (P/N 68079480AA Module - Power)
2. Control Assembly, Instrument Panel HVAC (P/N 68111109AQ Control - A/C and Heater)

The labor and parts were covered under the extended service contract so the total bill was $100.00. The parts replacement seemed to have fixed the problem.

However, over the next few weeks the A/C blower problem returned intermittently. It seems to be a problem when the temp is around 80 degrees or higher and the car has been sitting in the sun. The problem again happened on 6 October (a warm day) and it was exactly the same problem originally described.

Jeep is going back into the shop on 10 October 2016 for another try at fixing the problem.

 

Took it back into the shop and they played around with it for over an hour. It was a cool day so the symptom never reappeared. They did make a note in their computer log so when I come back in early summer next year with the same problem maybe we can pick up where we left off. At least they didn't charge me for this visit.

 

I had the same problem however, it only occurred after the PCM was replaced.

 

Hey Guys, I'm new to the forum. I have 2011 Grand Cherokee Overland and I am having the same issue as originally posted. Through my research so far, I see numerous people have had a similar issue but I haven't been able to find a clear solution to the problem It just started about 2 weeks ago and we live in Vegas, so heat is constant here. I was wondering if there ended up being an "official" or "unofficial" resolution to the problem.

I have already replaced the Blower Resistor P/N 68079480AA Module but that didn't work. I've checked the connectors on the wires and back of the control assembly for anything that would indicate overheating/melting pins/wires but everything appears to be fine. Very frustrating issue.

The jeep has caused us a lot of heart ache over the years with random repairs and we trying not to get rid of it since it's paid for (don't want another car payment). So any help and advise would be great.

In the meantime, I will look into Passenger Side Blend Door that was linked.

Thank you again in advance!

 

Recalls and TSB's (technical service manuals) are linked here
Jeep Grand Cherokee WK2 - 2011-2019 Grand Cherokee Service Bulletins and Recalls

 

The A/C blower motor cycling on and off is definitely the A/C system informing you of a problem. It's identifying a fault.

That fault is usually a broken blend door actuator gear on the driver or passenger side. If the blend door motor actuates past its normal travel... the A/C unit acts in this manner.

Both driver and passenger side blend door gears can be replaced without replacing the entire blend door assembly. Most dealers want to replace the entire blend door assembly which is a $1200+ fix... but it's always a simple $3 external gear that goes bad.

The passenger side blend door gear is a cinch to replace behind the glove box... but the driver side can also be done with a bit of console trim removal and patience.

I paid an independent mechanic found on Craigslist $60 labor to install a new driver side blend door actuator motor and gear... and invested about $40 in a new Mopar OEM blend door motor and gear on Ebay. About $100 invested. They did an awesome job and the blower issues ceased completely. It's been working pefectly for over a year now.

 

I have an issue with my driver side temp not working. actuator motor and both gears are fine but what I did notice with the motor out and plugged in, when you adjust the temp for driver side only, the actuator motor just keeps rotating in one direction or the other so if that was actually back where it was supposed to be, it would jam the blend door to one extreme or the other and eventually break the gears or burn out the motor. could it be that I just need a new control panel?

 

Here's my problem... My wife's 2011 JGCL has 102,000 miles. The battery light was on so I took out the battery and had it checked at AutoZone and they told me it was fine, just needed a charge. I assumed that the alternator was bad. I put the battery back in and drove it about a mile to go get some lunch.

The electronics in the car went crazy, wipers came on, warning lights on the car came on, AC stopped (blower, etc), radio, you name it. I thought it was possessed and then the car stalled and had almost no power at all and evenuqtlly (less than a minute) zero volts. I couldn't even get it out of park or have the hazard lights on since was stuck in the middle of busy street.

Long story short, my mechanic said the alternator was completely shot and the PCM was burnt. He replaced both and flashed the PCM. I test drove it after he fixed it and the fan blower cycles on and off as described. It is summer in Arizona and it is plenty hot. If I drive the car for awhile, maybe 15 minutes the blower stays on, however the cabin never really gets cool, not bad but not that cool either on full blast.

The A/C compressor stays on. The accumulator is quite cold to the touch. I replaced the blower-resistor module from Chrysler. No help, the problem remains. A digital food thermometer in the vent reads 52 degrees on low and 59 degrees on high fan (fahrenheit). My Honda Ridgeline reads 46 and 52 on the same day at roughly 100 degrees outside.

Reading this it seems like trying the actuator gears is usually a win, but in my case, it seems highly unlikely that a mechanical problem would happen the same time as an electrical problem. Could my original PCM or other electrical short caused the actuator gear(s) to break somehow, like making the actuator motor fluctuate and break the gears, or should I get a new temperature control module? I'm thinking the latter since maybe it shorted / fried something in there.

 

Update: passenger side gear was broken.

Been reading all of these and I just did a test where I had my drivers side low and passenger side high and that was correct, when I had my passenger side low and my drivers side high though my passenger side was coming out warm. Does that mean I need to replace the gear that's on the passenger side? Behind the plastic cover on the right hand side? Any confirmation will be greatly appreciated thanks.