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11-20-2014, 03:41 PM
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#1
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Senior Member
Alpine Owners Club
Join Date: Jan 2006
Location: West Covina, Ca 91791
Posts: 123
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Dash Air Problem
Our dash air will shutoff (looses power to compressor clutch) after 30 to 45 minutes if ambient temp is 80 degrees or above. If ambient temp is below 80 degrees it will run all day.
We have done the following to correct the problem, but these changes have not solve the problem.
1. Check system for leaks and recharged system.
2. Replaced temp switch.
3. Added pressure switch and relay to turn on hydraulic fan if high pressure side get to 240 psig.
4. Installed idiot light in power line to clutch. To tell if there is power or not when system quits.
Does anyone know if there is an ambient temp sensor in the system?
Does anyone have the electrical schematic for the dash air system?
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Dennis And Sally
2005 40FDQS
ACA & SoCal
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11-20-2014, 04:27 PM
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#2
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Senior Member
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 19,925
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You'd get more help if you could identify either the A/C manufacturer or the engine/chassis.
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Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
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11-20-2014, 04:42 PM
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#3
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Senior Member
Alpine Owners Club
Join Date: Jan 2006
Location: West Covina, Ca 91791
Posts: 123
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I did identify. It is a 2005 Alpine. All Alpines use the proprietary chase designed by Western RV.
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Dennis And Sally
2005 40FDQS
ACA & SoCal
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11-20-2014, 06:26 PM
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#4
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Senior Member
Join Date: Nov 2005
Posts: 7,822
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Interesting--I just completed a re-design of the dash A/C on my 03 Alpine. More on that later. Since yours is an 05 and has an electronic fan controller interface, the early model wax valve issues dont apply. Ref my re-dsign, I moved the condensor forward to the fender-well area in front of the pass wheel [mid-door], and added electric fans which by- passed the engine fan control issues altogether.
I havent torn into the the control head in the dash but what I found was that my compressor was running continuously if the on/off switch was in the A/C position--no cycling, no modulation based on ambient temps.
Sounds like your trimetic [sp] switch is reacting to freon over pressure and is shutting down the compressor. I understand you added a controller to active the engine fan but do you know what the actual freon pressure is when the system shuts-down. PM me and we can discuss off-line what I was able to learn about the system from my re-design effort.
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Old Scout
2015 IH45 Foretravel
2003 Alpine 40' MDTS [Sold]
New Braunfels, Texas
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11-20-2014, 09:08 PM
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#5
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Senior Member
Alpine Owners Club
Join Date: May 2004
Location: WA
Posts: 237
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This is all I have. A very very poor quality gif file. May be better than nothing?
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Gary & Renee
Mojo & Jetta
2006 APEX, Grand Cherokee
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11-21-2014, 02:56 PM
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#6
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Senior Member
Alpine Owners Club
Join Date: Jan 2006
Location: West Covina, Ca 91791
Posts: 123
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Thanks' Gary.
Was not able to read what you sent as it was not clear.
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Dennis And Sally
2005 40FDQS
ACA & SoCal
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11-23-2014, 05:00 PM
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#7
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Senior Member
Join Date: Nov 2005
Posts: 7,822
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I am not the first to think of this nor the first to execute it, but I finally re-designed my dash A/C by moving the condensor from the radiator stack in the rear and placing it in the fender-well on the passenger side, in front of the wheel well [note: my coach is a mid-door]. I then added electric fans controlled by the compressor clutch feed wire to provide air flow during ops.
Basic problem with the old design is that 03 and earlier Alpines use a wax valve to control the engine fan so there is no interface between the fan and the A/C system's need for air flow. Result--poor air flow thru the condensor and recurring freon over pressure. During the change over, I also discovered that some of the desiccant pellets from the filter/dryer had broken free and were partially blocking the expansion valve.
Key challenge to the redesign was snaking a new A/C hose from the compressor in the rear engine compartment to the front fender-well. The fuel and water tanks make for a very close fit with the C-channel formed by the frame. Also discovered that, atleast on my coach, there was no apparent mechanism to cycle the compressor based on ambient or evaporator temps so my compressor was running continuously with the A/C select switch in the on position. This could be a wiring issue at the control head in the dash, but I decided to add a pre-set thermal switch on the evaporator suction line to create optimum compressor cycles....
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Old Scout
2015 IH45 Foretravel
2003 Alpine 40' MDTS [Sold]
New Braunfels, Texas
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12-06-2014, 10:45 AM
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#8
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Senior Member
Alpine Owners Club
Join Date: Jan 2006
Location: West Covina, Ca 91791
Posts: 123
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Thank's Old Scout for the suggestion. I still would like to solve the problem with out moving the AC coil.
Again I ask, does anyone have the full chaise wiring schematic.
__________________
Dennis And Sally
2005 40FDQS
ACA & SoCal
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12-06-2014, 02:54 PM
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#9
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Senior Member
Join Date: Nov 2005
Posts: 7,822
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Think if you did a pass-fail test on the lead wires passing thru the trimetic [sp] valve [next to the filter/accumulator], you would isolate your issue--just saying.....
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Old Scout
2015 IH45 Foretravel
2003 Alpine 40' MDTS [Sold]
New Braunfels, Texas
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12-06-2014, 07:01 PM
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#10
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Senior Member
Alpine Owners Club
Join Date: Jan 2006
Location: West Covina, Ca 91791
Posts: 123
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Scout can you better describe where this valve is located. Is it located on the front wall in the generator area?
__________________
Dennis And Sally
2005 40FDQS
ACA & SoCal
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12-06-2014, 09:53 PM
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#11
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Senior Member
Join Date: Nov 2005
Posts: 7,822
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Correct--its located on the front bulkhead [genset area but under the front cap, near the wiper motor], on the short A/C hose going from the filter/dryer canister to the expansion valve. It will have 4 wires coming out of it -- 2 are for an electric fan controller [not use by WRV]. The other two create the circuit between the dash controls and the compressor clutch.
This valve has a high and low PSI limit--low limit keeps compressor from running if freon[134a] is too low, the high limit keep the compressor from over charging the system--perhaps 350-400 PSI. My "guess" remains that you have an inline blockage or rear fan cooling issue that is causing the tri-valve to shut-down the compressor. As I mentioned earlier, one of the problems with my system was that desiccant pellets from the filter/dryer broke loose and partially plugged the expansion valve.
There are probably some differences between my 03 and your 05 [like the electonic engine fan control] but the ACME A/C systems are pretty simple--not many moving parts. Still curious to know what level the freon pressure is at when the compressor shuts down....keep us posted....
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Old Scout
2015 IH45 Foretravel
2003 Alpine 40' MDTS [Sold]
New Braunfels, Texas
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12-06-2014, 11:20 PM
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#12
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Senior Member
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 19,925
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I had a van that suffered the same fate Old Scout was talking about, the filter/desiccant got out of the canister and contaminated the whole (dual evaporator) system. It was very expensive to flush and clean the lines. It showed up as poor cooling and high pressures.
__________________
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
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12-07-2014, 07:53 AM
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#13
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Senior Member
Join Date: Nov 2005
Posts: 7,822
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The reason I advocate doing a pass/fail analysis of the compressor clutch circuit at the the tri-valve, is to see if the problem is pressure vs electrical related. If pressure related, you should continue to get power from the dash controls to the valve but not beyond.
Because you have noted the problem occurs when ambient temps are higher, I doubt if it is electrical, ie, the tri-valve is doing its job as designed. If the tri-valve remains open and 134a pressures remain in range, then it could be electrical--perhaps the dash control head or a long shot being the engine fan interface circuit. Since you dont report higher than normal engine temps, the fan circuit is unlikely the cause.
My bet is still a high pressure issue based on a physical blockage or air flow issue.
PS--this is really getting in the weeds but I could not find a compressor cycling sensor/switch on my system, so I added an after market switch. Lack of a cycling switch will make an existing pressure issue worse.
__________________
Old Scout
2015 IH45 Foretravel
2003 Alpine 40' MDTS [Sold]
New Braunfels, Texas
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12-13-2014, 07:32 PM
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#14
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Senior Member
Join Date: May 2004
Location: Auburn, CA, Havasu, AZ & Mulege, BCS
Posts: 5,385
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I will have copies of a 2005 Limited chassis wire loom schematic at the Desert rat Rally, Jan 14th to 20th, Quartzsite AZ
These schematics show the pin-outs at each wire/connector end. E.g. there is a pulse-width-modulated wire end to the fan controller that exits the loom in a two wire connector; the diagram shows the plug end view so you can identify the end by use and physical config, and it tells you where to look for the other end of the wire in the loom, whether it be a splice, or another connector.
We have also started a wire marking "index" doc, see below for its current status.
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Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project
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