calling the chassis AC guru

[cannon man]

on my 2nd workhorse n same problem. doesn't get cold. been checked everybody says ok. it's the 20* thing. well, when its 90* or so outside 20* doesn't help much n no i dont wanna run the house air. don't want it to cool the coach, just blow some cool air on me.
my 95 f-150 makes 45* air when it's 90* out. so does my 99 saturn n my 04 dodge. so what gives? whats the diff?
will putting a big e-fan in front of condessor help?
thanks for any help. dave

[94-Newmar]

Have someone put some gauges on it and find out what your pressures on the low side are.

["007"]

If your having a mix of cool and hot air when slowing down the Evan control valve is not closing completely install a ball valve in one of the heater hoses.

[Flagelpater]

FWIW Not sure how big the house is but I am sure it is bigger than your truck cab. I am Not an expert, however, the unit works on the temperature of the input air v the output air. Efficiency is measured by the temperature drop. I am sure you already know this stuff but I just had to say it. If you want to compare the coach dash A/C to your truck A/C limit the amount of the house volume to the same as the truck. Put up a curtain so only that volume can be conditioned by your dash A/C. I bet you will be impressed, if the system is working. Even in my Chrysler T&C I can not keep it cool with just the dash A/C on. I need to turn on the aft A/C as well to keep up. The increase in volume there is nothing compared to my coach. I gave up a long time ago and turn On the GenSet and give the engine and its systems a break. Keeps us nice and cool, and not much more in fuel consumption either.

[cannon man]

checked preassures twise said ok.
knew about the evans valve. not the problem.
i'm taking the temp at the dash outlet. thermo inside.
thanks dave

[dieselclacker]

cannon man,

If your A/C is operting properly, and is fully charged, you should see discharge air from the dash ducts in the forty degree range. Discharge temps will vary with humidity, temp and volume of air crossing the condenser. I live in simi-arrid area, and consistantly see 42-43 discharge temps on 90 degree days. You are right 70 degree discharge air on a 90 degree day is not enough cool. If this is your case, you should take the advice of the above posts, regarding being fully charged, not taking in any air from the engine compartment into the A/C evaporator case, and making sure the hot water control valve is truely off. Flagelpater is correct, in that even a properly operating dash A/C system will not cool the volume of surrounding air down to a comfortable level in most motorhomes. It should however feel cold when it blows directly on you, and this helps somewhat. What I do sometime is run the house airconditioning till it gets cool inside, then shut it down and continue with the dash air only. Works for me.

Dieselclacker

[mfire1339]

Cannon man, You need to find someone who "wants" to fix it right. My 2004 W-22 chassis a/c will frost you. My complaint is it gets too cool on my hands and knees. The system is capable of cold air. I would make sure both electric fans run constant with a/c on. Next make sure recirc door seals. Next blend door seals as it should. All play a part in the temp game.

Mike

[Flagelpater]

FWIW Check the inlet temperature to the dash unit as well as the outlet temperature. I believe a 30 degree drop is optimum. These rigs are very big greenhouses. My unit only goes into what is normally called Recirculate mode when selecting Max Cold. I do not have any other switch to get into this mode. Simply turning the knob to A/C and I will be trying to cool outside air inbound on the fly, not a very good idea on a hot day. Dieselclacker also has a good idea as far as pre-cooling with the house unit first, that will provide you with a lower inlet temperature. I sometimes do this as well. I have a cloth curtain that I use for my trip South every December. It goes from floor to cieling, wall to wall right behind the front seats. It reduces the amount of cabin I am trying to heat or cool, no good with extra passengers! Without it I need to run the furnace to be warm at the drivers seat. The faster you drive the more contact cooling, or heating, you are going to get as well. Going slower on very cold days, around 32, will make a substantial difference in heat mode and I would expect the same while trying to cool.

[a k]

Get a shower rod and a clear shower curtain and hang it up behind your seats.Close off the rear of the coach if you don't want to run the house air.

[cannon man]

there are no fans on these models.

[jdsr]

You might want to check your vac lines. Had problems with mine and the last shop wanted to rpl comp and or evap. Turns out my problem was a blue and green vac line. I had to look real close for hairline cracks. I rpl all the vac lines and problem solved.

[mfire1339]

Quote:

Originally Posted by cannon man there are no fans on these models.

Cannon man, I'm talking about the two fans in front of the radiator.

Mike

[George Z]

Quote:

Originally Posted by jdsr You might want to check your vac lines. Had problems with mine and the last shop wanted to rpl comp and or evap. Turns out my problem was a blue and green vac line. I had to look real close for hairline cracks. I rpl all the vac lines and problem solved.

Agreed totally, a vacuum leak will play havoc with the cooling and heating system
George

[edgray]

Quote:

Originally Posted by mfire1339 Cannon man, I'm talking about the two fans in front of the radiator. Mike

Mike:
FYI, WCC did away with the 2 fans when they went to the improved "cool pack" a couple of model years ago. Ed