Why did the Mobility Express people check every ground? Did they have a reason to suspect a grounding problem? Do they have competent A/C service people in their shop?
I can understand your Chrysler dealer suspecting a problem caused by the conversion, because every wire and line going between the front and rear of the Pacifica has been replaced and rerouted, often with a longer one. (Your Pacifica has a rear secondary A/C unit.) However they should still be able to tell you what is causing the problem. You will have to pay for the diagnosis. What I don't understand is Mobility Express's unwillingness to deal with Chrysler directly for you.
Intermittent hot/cold A/C problems can be caused by excess moisture in the refrigerant. That could happen when the system was opened to replace the lines to the rear unit.
PS. I read in another thread that a failed compressor clutch has been causing intermittent hot/cold problems. This is a Chrysler problem.
Here's the complete rundown:
The van only had 3,590 miles when I purchased it and it now has around 8500. I drove the van problem free until late April, early May, which is also when I started running the A/C on high. Around that time I noticed 2 issues and I made an appointment at Phillips CJD here in Ocala. The 2 issues were 1) the rear a/c would barely blow regardless of the fan setting and 2) the whole a/c would shut off and then come back on by itself a few seconds later.
On my first service visit I was told that there was a black box in the way and that it might have something to do with the problem. I was also told that I would be charged $200-300 if Chrysler had to uninstall the box to get to the a/c. It was recommended that I should first take the van to Mobility Express because it was probably something they did. Keep in mind they did not check anything or do anything to find the problem, they blamed the conversion without any evidence whatsoever. Now I make an appointment at Mobility Express where the tech takes less than 5 minutes to show me the black box. The box is roughly 6 in by 6 in, and about 3/4 in thick. It is not mounted to anything and can be easily moved out of the way since it has about 10 feet of wire attached. Now I make my second appointment at Phillips Chrysler CJD.
On my second visit I was told they found the problem and it needed a new module. They did not have it there so it would have to be ordered.
On my third visit which was the following week, they replaced the module. Well this fixed one issue which was the rear a/c vents were now blowing however on my way home the same issue of the a/c cycling off and on by itself continued to happen. Now I make another appointment at Phillips CJD.
On my fourth visit to Chrysler I was pulled into a room with the service manager Gary and the technician named George. Here I was told that they are getting strange voltage readings and it had to have something to do with reduced effort steering installed by Mobility Express. Now I make another appointment with Mobility Express. At this appointment the tech noticed some codes having to do with communication with the A/C, sorry I don't remember exactly what he found but he updated the VMI software and cleared all the codes. I am told again that nothing regarding the conversion or reduced steering would cause these issues. Therefore I make another appointment at Chrysler and I’m told I need to leave the van. Over the next few days (while waiting to bring my van in again) a third problem surfaced. Now, not only would the a/c cycle off and on but when it came back on sometimes it would blow cold and sometimes it would blow hot air. I started researching this on my own and found similar issues by other Pacifica owners at pacificaforums.com. I found 2 Manufacturer Communication Numbers which I believe reference my van issues, they are 24-009-16 and 24-011-16 and they discuss replacing the compressor and some other parts.
On the fifth visit to Phillips Chrysler, I told Gary about the third issue and I gave him copies of the MCN’s that I printed. I then drove back home and my wife drove my van back and dropped it off. I have no other way of getting around and renting a wheelchair accessible vehicle is expensive. On Tuesday, June 25, they called and said my van was ready and they had replaced the module (sound familiar). Well my wife went to pick up the vehicle and before she got out of the parking lot the a/c shut off and came back on by itself. She then took one of the service guys named Scott for a quick ride and the problem continued with Scott in the vehicle. She explained to him that it’s dangerous for me to drive a vehicle in Florida in the summer without a/c. He says he understands and they will get it fixed. Then on Friday, June 28, I got a call from Scott saying the van was fixed. He said the whole problem the whole time was the reduced effort steering was wired wrong by Mobility Express. Scott said they unplugged the reduced effort steering, cleared all the codes and test drove the van and it’s all good except I need to pay $360 for their time figuring out what was wrong. I asked if my wife could test drive the van first before we paid $360 and he said yes. Well again my wife did not even take the van out of the parking lot and the a/c shuts off and comes back on blasting hot air. Scott got in the vehicle and they had to turn the a/c off and then back on to get it to blow cold again. This is on Friday June 28, so we leave the van so they can continue looking into this the following week. During the next 2 weeks various things are happening. They assign it to a different tech and they try replacing the center stack, same problem so they put my center stack back in. Next, Chrysler cares wants them to tests the a/c grounds. Their response is the grounds have been moved and they will no longer work on the van unless the wiring is returned to it's factory
state. Therefore we pick up the van on July 12.
At this point I called Mobility Express and tell them to get this figured out and I drop the van off with them. They work over the phone with a VMI tech and go through all the grounds and wiring. They did find one issue in the B Pillar where a wire had come loose. That was repaired, reduced steering was connected back up (with a new harness because Chrysler damaged the original harness), all codes were cleared and of course they test drove the van and the same problem was still there. They believe this is a Chrysler issue.
Now that I've gone through everything what is actually happening is this: The issue occurs when the front air blower is set on 5, 6 or 7(mostly on 7). I can run it on 4 all day and seem to have no issues other than it doesn't seem to blow as cold as it should. The rear air doesn't seem to have any impact regardless what it is set to, but when the a/c shuts down it shuts front and rear down and then comes back on. Something related to voltage seems to be the cause because voltage drops from around 14 down to around 12.6 for a split second and this is when the issue occurs. I know this because I have the voltage displayed on the console and I have watched closely. Also it only happens when letting up on the gas or going really slow. It doesn't seem to happen when accelerating. To me this sounds like the compressor pulley or the fan motor has a glitch and is causing the voltage to drop for a split second. But I am guessing.
My hope (and I also did a facebook post) is that between Chrysler, VMI and Mobility Express somebody can get together and figure this out.
Thanks for any input.