Factory Chassis A/C not working

blightle · 04-28-2010, 06:24 PM

When I picked up my 2011 Georgetown 350, the dealer had noted that the factory chassis A/C was not working. Compressor would not engage.

They were unable to locate the problem and said that I would need to take to Ford. Took the RV to Ford today and they have not been able to locate the problem either. They asked me for a wiring diagram of how Forest River hooked up the A/C between the coach and the chassis. Of course I don't have that wiring diagram. Trying to get from Forest River.

Anyone else ever experience something similar or does anyone have an A/C wiring diagram for a late model 350? Freon levels are good, pressure switch works fine, etc. Ford said they checked all of the normal things and they are stumped. They want the wiring diagram to hopefully pin-point the problem before tearing everything apart.

NWJeeper · 04-28-2010, 07:44 PM

Quote:

Originally Posted by blightle

When I picked up my 2011 Georgetown 350, the dealer had noted that the factory chassis A/C was not working. Compressor would not engage.

They were unable to locate the problem and said that I would need to take to Ford. Took the RV to Ford today and they have not been able to locate the problem either. They asked me for a wiring diagram of how Forest River hooked up the A/C between the coach and the chassis. Of course I don't have that wiring diagram. Trying to get from Forest River.

Anyone else ever experience something similar or does anyone have an A/C wiring diagram for a late model 350? Freon levels are good, pressure switch works fine, etc. Ford said they checked all of the normal things and they are stumped. They want the wiring diagram to hopefully pin-point the problem before tearing everything apart.

From the literature that came with our rig the A/C is by a 3rd party supplier, not Ford, not FR. FR installs it once the shell is put together. Ours had no wiring diagram.

blightle · 04-28-2010, 08:11 PM

Thank you for the reply. I agree that the A/C blower, duct work, etc. are from a 3rd party but I also understand that the A/C compressor on the engine and part of the wiring harnesses are from Ford. Not sure about the freon canister. My understanding is that Forest River ties the third party components into the Ford compressor and existing wiring harness. I did a little looking and Ford has labels on all of the wires in the factory harness so that the RV manufacturer knows what to hook up where. Guess they did not get it quite right on mine. Also my Ford fuse block in the engine compartment contains an A/C relay, clutch fuse and an clutch diode so it appears to be a combination of two systems.

NWJeeper · 04-28-2010, 08:37 PM

Quote:

Originally Posted by blightle

Thank you for the reply. I agree that the A/C blower, duct work, etc. are from a 3rd party but I also understand that the A/C compressor on the engine and part of the wiring harnesses are from Ford. Not sure about the freon canister. My understanding is that Forest River ties the third party components into the Ford compressor and existing wiring harness. I did a little looking and Ford has labels on all of the wires in the factory harness so that the RV manufacturer knows what to hook up where. Guess they did not get it quite right on mine. Also my Ford fuse block in the engine compartment contains an A/C relay, clutch fuse and an clutch diode so it appears to be a combination of two systems.

That would make sense and they (Ford dealer) should be at least able to determine if the compressor is good or not by wiring +12volts directly to the clutch input on the front of the compressor to see if it engages, that would elimenate some of the possibilities. They should be able to get it figured out for you.

LadyWindrider · 04-28-2010, 09:33 PM

Don't have a wiring diagram, but I can tell you on 90% of vehicles how it works. AC switch on control panel operates the AC relay, sends 12 volts, through the diode,to the AC clutch on the compressor.
Oops, the 12 volts also goes through the low pressure and high pressure cutout switches. Also there is no freon canister, that is a drier or accumulator. You short the high and low switches to verify their operation. I would be looking at another dealer maybe. Any auto tech that knows anything about AC should know these things, especially a newer R134a system, as they are all the same from the major 3 manufacturers, and most foreign cars. I used to check all these before I ever needed or wanted a diagram. NWJEEPER is right, hook 12 volts to the compressor and watch for smoke. At least it will tell if there is enough freon to get cold. I also don't understand how they know freon levels are good or that the pressure switches work if they can't get to the compressor to engage. You can't tell freon level by static pressure, system must be running. Good Luck.

ronhanson · 04-28-2010, 09:36 PM

It could be something as simple as a wire or harness not being hooked up during assembly. I have a hard time believing Ford is at fault here since their QC is light years ahead of Forest Rivers or the AC vendor, but you're going to have to go through some work trying to figure out what is wrong and who is responsible. It won't be easy since you have 3 parties involved at this point. Ultimately, Forest River is responsible for their integrated product so I would get the factory involved if you haven't already. Dealers are mostly worthless if they cant turn a screw. The factory will green light any costs so you're not on the hook for anything.

Contact:

Mike Burns
Forest River Inc.
Warranty - Retail Motorized
Phone - 574-206-7603
Fax - 574-206-2484
Email - mburns@forestriverinc.com

blightle · 04-29-2010, 09:33 AM

This morning, Forest River sent me a wiring diagram for the 3rd party Evans Tempcon A/C system that was installed in my Georgetown. Thought others may find the diagram useful so I am uploading it here (thanks to NWJeeper telling me how to upload a file).

Will respond back once the Ford dealer determines the problem in case anyone else ever has a similar issue. Thanks for all of the replys. This is great forum!

NWJeeper · 04-29-2010, 10:54 AM

Thanks for the diagram. I have saved it to my "Georgetown Documents" file on my computer for later reference. I have managed to find .PDF files for almost all the documentation for our rig and have it all stored on the computer.

cfsoistman · 04-29-2010, 12:30 PM

If I'm betting on the solution to the problem. I'll take bad ground for $200. FR seems to rely on self tapping screws into the frame. They used an aluminum trim oval head type for the ground to my headlights with an oversized terminal round connector and a big washer. The aluminum oxidized, lost contact and I had no headlights. They also don't remove any paint where the terminal connector contacted the frame so the threads were the only source of contact. I drilled out the hole, wire wheeled off the paint and bolted the connector to the frame and then coated with battery terminal protectant. I'm eager to hear what they find.

blightle · 04-29-2010, 09:30 PM

So Ford figured out the problem with the A/C. Cfsoistman, you were half correct. Turns out that the Power Control Module (PCM) which is apparently the computer that controls most of the engine functions also controls the ground to the A/C clutch relay. The service tech said that the PCM was not controlling the ground properly. Apparently was not something a software flash would fix so a new PCM is on its way from the factory. Since it is a 2011 chassis, no one has this part in stock yet. Ford dealer did not even have a part number in the system and had to call Ford Engineering in Detroit to get a part number.

I have to hand it to the Ford service guys, I would have never found that one on my own. At least this was a Ford issue so there is no charge to me and no need for me to seek reimbursement from FR.

LadyWindrider · 04-29-2010, 10:05 PM

If the PCM controls the ground to the AC clutch relay, then your diagram in post #7 is useless, as it shows a hard ground to the clutch relay. I'm not trying to argue with success, glad they found something. I just don't see the PCM anywhere in the wiring diagram. Just making a note for those in the future, this wring diagram is missing something.

NWJeeper · 04-29-2010, 10:25 PM

Well, way to make things even more complicated Ford! Why in the world do they need the computer to control the ground. In most A/C applications the ground is just that, a ground! The 12 volt power to the clutch is switched on and off as needed for the sytem to work.

Give me simple and stop controlling everything with the stinking computer!

blightle · 04-29-2010, 10:43 PM

Windrider - keep in mind that the wiring diagram is just for the 3rd party A/C system. In the note in the upper right of the diagram it basically says that the "dashed" lines are illustrative of parts that may be found on the chassis side of the vehicle. Ford did say that the diagram was only somewhat helpful in that the colors of the wires were apparently different.

I too have no idea why a PCM would need to control the ground to a relay for the A/C unless there is something in the engine programming where in certain situations if there is a significant loss of engine power the PCM will shut down all but the most essential components to keep the engine running so that you can at least limp home.

LadyWindrider · 04-29-2010, 10:57 PM

Being "new", probably "CAN" and not OBD II, the PCM will control essential functions, even switch to 4 or 5 cylinders in case of overheat, and shut the AC off. It will also shut the AC under full acceleration. They have been doing this a few years. They usually do this with the AC control feeding the PCM, and the PCM feeding the clutch relay. Regardless, the clutch "ground" in the diagram must be wired back to the pcm, and is not a hard ground. I'm not trying to confuse, just help those that do their own work, and may reference this post in the future.

TulsaSteve · 04-30-2010, 12:02 AM

Quote:

Originally Posted by NWJeeper

Give me simple and stop controlling everything with the stinking computer!

This gave me a good laugh. I went down a 4.5% grade a few days ago and barely touched the brakes. The computer was working the transmission / engine like a dream and I just walked right down the hill while others were struggling.

Computers.. Can't live with em'... Can't turn em' off because we can't remember what happens if we do...

ArkyGeorgetown330TS · 05-11-2010, 07:49 AM

Well I am about to take my 330TS in for a few items to be fixed after our 2nd trip out. One is the dash air is not working. I have printed off the schematics posted above to take with me and hope it will help. The thing that gets me is we forgot to check the dash air when we did our PDI. I can only guess is because it was cold when we took delivery and did not even think to check it. Yes it was on the PDI and I just had a brain F__T and did not check it off. Oh well its like they always say.

cfsoistman · 05-11-2010, 11:52 AM

Quote:

Originally Posted by ArkyGeorgetown330TS

Well I am about to take my 330TS in for a few items to be fixed after our 2nd trip out. One is the dash air is not working. I have printed off the schematics posted above to take with me and hope it will help. The thing that gets me is we forgot to check the dash air when we did our PDI. I can only guess is because it was cold when we took delivery and did not even think to check it. Yes it was on the PDI and I just had a brain F__T and did not check it off. Oh well its like they always say.

Gotta be careful with those Brain F_ _ Ts, that where S_ _ tty ideas come from!

Good luck with the AC! Hopefully it will be something simple.

mbtelguy · 05-11-2010, 07:50 PM

The following site provides complete manuals/troubleshooting guides for Evans Tempcon including the FR provided schematic ( with explanation ) posted earlier. Good information to have.

Evans Tempcon, Inc

blightle · 05-25-2010, 09:13 PM

So I started this thread about a month ago and finally have a resolution on why my factory A/C would not work in my 2011 Georgetown. Ford spent almost 3 weeks working on my Georgetown. Numerous calls to Engineering in Detroit, calls to techs at Forest River about the wiring of the Evans Tempcon 3rd party A/C system, etc. Nothing was showing up as a problem. At one point Ford thought it was a bad PCM but after ordering a new one, later determined that the PCM was not the issue. Finally on Monday, they were running tests again and the PCM threw an error code for the first time. Turns out that the low pressure switch was bad. Never showed up in all the times they had run the test before but it must have deteriorated to the point that it would send a trouble code or something. Must have been a new pressure switch design for 2011 because they had to have the switch overnighted from Detroit. Got it this morning, installed it and now the A/C is ice cold - finally. Just in time for Memorial Day Weekend and our first real outing with the RV.

You may also like: