fans that cool allison & a/c

[faye]

we have our 2004 national seabreeze in because the a/c blows out hot air. the shop says going down the road it cools after they have added freon but when they stop, heater air/hot air comes out. they wanted to know if the two fans that cool the a/c & allison if they run on two speeds(high & low), does anyone know????????? i have read that our problem is common on this wh chassis.....the shop people said the high side pressure builds up and causes a release of the freon and the a/c starts blowing hot air. we are lost and don't understand the problem.. are there solutions to this that will not cost thousands????????if someone could answer the 2 questions please. thanks

[DriVer]

Quote:

Originally Posted by faye we have our 2004 national seabreeze in because the a/c blows out hot air. the shop says going down the road it cools after they have added freon but when they stop, heater air/hot air comes out. they wanted to know if the two fans that cool the a/c & Allison if they run on two speeds(high & low), does anyone know?

As far as I know, the fans are variable and they will speed up or slow down as required. Basically I think the fans are ON or OFF but there isn't a HI and LOW.

Quote:

i have read that our problem is common on this wh chassis.....the shop people said the high side pressure builds up and causes a release of the freon and the a/c starts blowing hot air. we are lost and don't understand the problem.. are there solutions to this that will not cost thousands????????if someone could answer the 2 questions please. thanks

My Workhorse Service Center has not been challenged when working on my AC system. Have them call Larry's Auto Clinic in Myrtle Beach and see if he's not too busy to take a question. He's very good with AC issues. They close at 5:00PM EST

[Gary RVRoamer]

The engine controller turns the electric fans on/off as needed, based on coolant temperature and load.

I've not heard of a/c problems with the Workhorse, but I no longer own one. In the five years we drove our W22 (A Dolphin LX), the a/c always worked fine except when a temperature mixing valve failed. That was a National RV problem, not Workhorse.

I think you need a shop that knows a bit more about air conditioners. Go to a shop that specializes in automotive a/c.

[faye]

thanks for the replies.

[az bound]

You may want to check the Evans tempcon valve to see if it allowing hot water to circulate through the heater core while the ac is on. I had that problem and Evans replaced it free of charges. They had a bad batch of valves and your model year falls within that timeframe.
To do this check have the engine up to temperature and with the valve in the closed position, check to see if the outlet side hose is hot, if it is hot the valve is allowing hot water to pass through to the heater core. Good luck

[speed racer]

With the A/C on the fans should run all the time. What you are saying sounds like a pressure differential problem. A problem like low head pressure bad expansion valve(orifice tube) or a weak compressor.

[Gary RVRoamer]

The two auxiliary electric fans on a Workhorse do not run all the time, a/c or not.

[speed racer]

Quote:

Originally Posted by RV Roamer [Gary] The two auxiliary electric fans on a Workhorse do not run all the time, a/c or not.

Mine must be broken then because on my 04 W22 the fan comes on when I turn the A/C on and stays on till I turn it off. I don't think I am going to fix it though because the A/C works great.

[edgray]

Quote:

Originally Posted by speed racer Mine must be broken then because on my 04 W22 the fan comes on when I turn the A/C on and stays on till I turn it off. I don't think I am going to fix it though because the A/C works great.

Speed racer: I think yours is operating as designed. According to the WCC Chassis Guide:

IF the AC is ON and the engine is at normal operating temp then both fans are "susposed" to be running.

The electric fans can also be turned on by the ECM even if the AC is OFF. This can occur if the motor is at unusually high temperatures.

That is the way my 2003 works.
Ed

[Gary RVRoamer]

I guess I am mostly in error about the fans and a/c, then. It's been almost 5 years since I owned one (a 2002 W22). Mea culpa. I should have read my Workhorse ChassisManual, as Ed did.

My WH Chassis Guide says...

Quote:

These fan(s) are controlled by the Powertrain Control Module (PCM) and operate whenever the dash air conditioning compressor is operating or if the engine temperature is above 221 degrees F.

Note that the Chassis Guide says "when the compressor is operating", which is not always the same as "AC is on". The compressor runs as needed to provide cooling and cycles on and off, so the fans may cycle off too.

[scoutmstr]

Ed and Gary

What page in the WCC manual is the reference to the fans? Mine used to work when A/C compressor was engaged but now they (all three) don't. A/C still blows cold though. Mine has the three fans because I added the WCC kit offered some time ago which added a condensor with a fan.

[Flossy]

I had a problem with my AC blowing hot or room temp air. The culprit was the heater valve allowing some hot water to trickle by and negate the AC. The solution was to install a manual valve on the heater hose to stop the flow of water. In colder weather I can turn it back on.

We traveled through 100 plus weather and the AC kept us comfortable. the only time I turned on the roof air was when I stopped to get gas and everything heated up.

Dave

[RottenRalph]

I just vacuumed and charged my AC while the engine was cold and running. The electric fans did not come on until the AC head pressure was about 250PSI. Or it could be that after idling a few minutes, the engine temp kicked in the fans.

[Gary RVRoamer]

Quote:

What page in the WCC manual is the reference to the fans?

In the pdf version of the WCC manual I have, the fans are discussed on page 89, the Air Conditioning section.