Replacing old dash AC 1994 Itasca Suncruiser

[semcha]

I have a 1994 Itasca Suncruiser on a Ford F53 chassis. It looks like I need to replace the dash AC controller because changing the settings on it doesn't affect the vacuum on any of the outgoing lines. So my vent doors don't open and close, and I don't get cold air, even on MAX AC. The vacuum hose going to the unit is good and does pull a vacuum.

Problem is, this is an old system, so I'm not having a lot of luck finding a decent replacement. Anyone have experience with this?

Thanks!

[lonfu]

on my 98 itasca, p30 chassis, turned out the ecm was not activating the ac compressor so that had to be replaced. I screwed closed the vent door. 2nd thing I did was to verify that the blend door was working. when the vent doors are screwed closed all the air is drawn from the interior of the coach thus making it colder. if the blend door is not working then you get a mix of hot and cold. next I verified that my heating valve was opening and closing. finally I changed to Enviro-safe coolant. These changes brought my center vent temp down to 39 degrees ambient 100 while running. Oh yeah, almost forgot, had to put a switch on the electric fan in front of the radiator to shut it off. The stupid thing was cooling the fan clutch and causing it to disengage and cause the AC temp to go up as well as the engine temps.

Current quality Newmar moho: screwed vent door shut, replaced heat valve with ball valve because original valve is poorly designed. There is no blend door, use switch to activate valve as heat and AC coils are one unit so original valve allowed the coolant to pass and heat the air whill trying to cool it. installed air filter over inside air intake to collect dust. AC center vent is 37 degrees ambient 100 again used Envirosafe coolant. Heating now works correctly in winter.

I would recommend some kind of insulation foam for your evap cover as they seem to be rotted by the heat. Evans AC company does a poor engineering job on the older moho units. If you can't find a replacement at a reasonable cost then I'd make one from sheet metal and insulate the exterior.

AC techs will recharge your system but won't change the components. They will tell you that discharge air for moho's will be 40 degrees below ambient is normal. this is not true. Evans original designs were not very good and you will need to re-engineer the components. Most AC techs are parts replacer's and not engineers so don't expect them to do this for you. Think of it like asking a nursing assistant to do open heart surgery. Good luck.

[153stars]

Enviro-safe coolant . Put it in daughters old Honda one year there was shortage of R134A like $30-40 a can . You could see your breath in front of vent going down the highway. Never feel or see RPMs drop when compressor kicked in a stop light.

[153stars]

Take a pic and post The IRV2 app is easiest way post a pic.
With exception of fancy headlights like from a BMW. A lot of parts they choose are usually popular domestic auto maker years older than coach.

[GypsyR]

The controller in my Ford coach with an Evans system for some reason appears to be that of a late 1980's Dodge van for some reason. I recognized it as soon as I saw it. A picture might help identify what yours is.

Isn't that Envirosafe stuff basically propane?

[lonfu]

Originally Posted by GypsyR

The controller in my Ford coach with an Evans system for some reason appears to be that of a late 1980's Dodge van for some reason. I recognized it as soon as I saw it. A picture might help identify what yours is.

Isn't that Envirosafe stuff basically propane?

yes, kinda sorta... but a mixture of gasses. Now don't go complaining about how explosive it is...most ac systems only have about a quart vs. propane storage for the gas appliances. 20 to 40 gallons.

[153stars]

Has highly refined laboratory quality propane and butane with different ratio to match different R types with kind of a pine smell for leak detection, The odorant in LP and Nat. gas is not good in AC systems.

Originally Posted by lonfu

yes, kinda sorta... but a mixture of gasses. Now don't go complaining about how explosive it is...most ac systems only have about a quart vs. propane storage for the gas appliances. 20 to 40 gallons.

[Ray,IN]

Originally Posted by lonfu

on my 98 itasca, p30 chassis, turned out the ecm was not activating the ac compressor so that had to be replaced. I screwed closed the vent door. 2nd thing I did was to verify that the blend door was working. when the vent doors are screwed closed all the air is drawn from the interior of the coach thus making it colder. if the blend door is not working then you get a mix of hot and cold. next I verified that my heating valve was opening and closing. finally I changed to Enviro-safe coolant. These changes brought my center vent temp down to 39 degrees ambient 100 while running. Oh yeah, almost forgot, had to put a switch on the electric fan in front of the radiator to shut it off. The stupid thing was cooling the fan clutch and causing it to disengage and cause the AC temp to go up as well as the engine temps.

Current quality Newmar moho: screwed vent door shut, replaced heat valve with ball valve because original valve is poorly designed. There is no blend door, use switch to activate valve as heat and AC coils are one unit so original valve allowed the coolant to pass and heat the air whill trying to cool it. installed air filter over inside air intake to collect dust. AC center vent is 37 degrees ambient 100 again used Envirosafe coolant. Heating now works correctly in winter.

I would recommend some kind of insulation foam for your evap cover as they seem to be rotted by the heat. Evans AC company does a poor engineering job on the older moho units. If you can't find a replacement at a reasonable cost then I'd make one from sheet metal and insulate the exterior.

AC techs will recharge your system but won't change the components. They will tell you that discharge air for moho's will be 40 degrees below ambient is normal. this is not true. Evans original designs were not very good and you will need to re-engineer the components. Most AC techs are parts replacer's and not engineers so don't expect them to do this for you. Think of it like asking a nursing assistant to do open heart surgery. Good luck.

100° inside your MH? That would be harsh to withstand.
Ambient temperature is not outside temperature. When discussing air conditioning ambient temperature is INSIDE return air temperature. The DELTA is the difference between inside return air (ambient temperature) and chilled air temperature.


reference: https://www.btrac.com/documents/svc-...i-feb-2011.pdf

[lonfu]

Originally Posted by Ray,IN

100° inside your MH? That would be harsh to withstand.
Ambient temperature is not outside temperature. When discussing air conditioning ambient temperature is INSIDE return air temperature. The DELTA is the difference between inside return air (ambient temperature) and chilled air temperature.


reference: https://www.btrac.com/documents/svc-...i-feb-2011.pdf

Ok, one more time... I learned AC in the early 70's. Ambient temp was the outside air temp outside the coach away from the engine. Yes, all the college books, training manuals have decided that ambient temp means a whole bunch of other things, depending on the book you read... Think of it like junk... in my day it referred to unused items that were stored in ones garage and was sold off in garage sales. Today junk refers to our male groin area....

for some reason the more educated we become the more stupid we become... perhaps if we spent less time naming and complicating things perhaps we should instead spent more time training our techs to diagnose and repair things. My mom use to call this "use your brain"...

[lonfu]

Originally Posted by Ray,IN

100° inside your MH? That would be harsh to withstand.
Ambient temperature is not outside temperature. When discussing air conditioning ambient temperature is INSIDE return air temperature. The DELTA is the difference between inside return air (ambient temperature) and chilled air temperature.


reference: https://www.btrac.com/documents/svc-...i-feb-2011.pdf

Actually, that a pretty good basic ac document, I downloaded to read later... I like to read tech manuals before I go to sleep.

remember, don't throw out your junk.... you might get arrested...

[lonfu]

Dont know if someone all ready mentioned it, but R134 is no longer being installed in new vehicles. R1234yf is the newest stuff that is being installed in new cars and trucks. It is flammable just like the Envriosafe coolant. Gee, could it be the same thing??? duh...

stuff in AC system is called: coolant, ac gas, refrigerant and the list goes on and on...

just depends on the book you read...

[semcha]

Here is the pic of the AC controller.

Originally Posted by 153stars

Take a pic and post The IRV2 app is easiest way post a pic.
With exception of fancy headlights like from a BMW. A lot of parts they choose are usually popular domestic auto maker years older than coach.

[GypsyR]

From/for a 1993 Dodge Tradesman or B150 van I'd say. I don't recall the graphics being in color though. White silkscreen on black plastic are what Chrysler controls I have in my F53 are which I am sure are Dodge van or pickup controls from about 1990.

[Ray,IN]

Originally Posted by lonfu

Ok, one more time... I learned AC in the early 70's. Ambient temp was the outside air temp outside the coach away from the engine. Yes, all the college books, training manuals have decided that ambient temp means a whole bunch of other things, depending on the book you read... Think of it like junk... in my day it referred to unused items that were stored in ones garage and was sold off in garage sales. Today junk refers to our male groin area....

for some reason the more educated we become the more stupid we become... perhaps if we spent less time naming and complicating things perhaps we should instead spent more time training our techs to diagnose and repair things. My mom use to call this "use your brain"...

How then do you refer to return air into the plenum? That reads like you forgot what you learned 50 years ago.