Community Forums

K Man · 10-05-2009, 10:10 AM

I have been reading through many posts on Workhorse and Newmar forums, as well as RV appliances forum.

The dash air in our '04 gas Kountry Star is only blowing warm air. The Workhorse manual shows a Delphi/Harrison compressor. All the posts I have found talk about an Evans compressor.

I am confused as where to look for assistance with this problem. I am hoping it is only a matter of being recharged since I do not use the dash air very often.

Newmar supplies the evaporator core - Workhorse the rest. I am not certain which needs repair.

dieselclacker · 10-05-2009, 04:01 PM

K Man, you are correct on the make of compressor (Delphi). The Evans valve mentioned in the many posts you have read is a vacuum operated valve that controls the flow of coolant thru the heater core. Many coaches equipped with this valve have a problem of not shutting off completely, thus causing warmer than normal air to be discharged from the air conditioning, (the heater core and the evaporator for the A/C share the same case). Don't know if your coach is equipped with this brand of valve or not.
Have you checked all the fuses for the A/C? Can you hear the clutch on the compressor engage when you turn on the A/C? Turning on the defroster of your heating ventilation system should also cause the clutch to engage, and the A/C to operate, it does this to remove the moisture from the air and clears fogged windshield faster. There is a low pressure switch in the liquid line of the A/C that cuts off the compressor in case of low refrigerant due to leakages of oil and coolant that could cause damage to the system. If the system needs refrigerant, this switch will keep the clutch on the compressor from engaging. If this is the case, the system needs to be taken to an A/C shop for leak testing and repair of same.

Dieselclacker

Spoonman · 10-05-2009, 04:09 PM

Many owners, including myself have had problems with evans temperature control valve not working properly. This valve is located in the line that supplies hot water from your engine to the heater core. When this valve malfunctions the hot water going through the core is too much for your ac to handle.
When you put your controls on ac, check hoses to heater coil and if they stay hot your valve is sticking open. Some owners have changed this valve and others have installed a ball valve to manually stop hot water circulation.
Either way it is much cheaper than ac repairs.
Good luck

edgray · 10-05-2009, 04:43 PM

Quote:

Originally Posted by dieselclacker

K Man, you are correct on the make of compressor (Delphi). The Evans valve mentioned in the many posts you have read is a vacuum operated valve that controls the flow of coolant thru the heater core. Many coaches equipped with this valve have a problem of not shutting off completely, thus causing warmer than normal air to be discharged from the air conditioning, (the heater core and the evaporator for the A/C share the same case). Don't know if your coach is equipped with this brand of valve or not.........
Dieselclacker

K Man, what DC posted and I've quoted above is correct....but I want to add that "some" of the Evans valves are electrically operated, not vacuum. Mine is electric and has been replaced twice because it would not totally stop the flow. Apparently the coach builder decides whether to operate the valve from a vacuum or electric dash control knob. You can "test" to see if the valve is the problem by simply removing the hose going to it and plugging the hose with a tapered dowel or a bolt of the correct diameter. Good luck, ED

K Man · 10-05-2009, 05:25 PM

Dieselclacker:

Thank you for your reply. As far as I know, the defroster is working properly. I do not know where to find the Evans valve you mentioned. Nor do I know if it is electric or vacuum. I am taking the unit in on Wednesday to a Workhorse Centre. Hopefully, they will be able to solve the problem at a reasonable price.

"007" · 10-05-2009, 07:23 PM

If you look to the left of your hood opening you will see the Evans heater/AC unit. The ball valve is installed in one of the heater hoses. If you look at picture to the left of valve you will see the Evans control valve with two heater hoses working through it.
The ball valve will stop hot water from entering the heater portion of Evans unit so AC doesn't have to overcome the hot water in heater portion that ball valve will close off from heater.
Some people have received new control valve from Evans but not sure now that they will still replace it gratis. Easier to just place the ball valve.

K Man · 10-05-2009, 08:46 PM

Thanks, 007. I will go to where the unit is parked tomorrow and have a look.

jdsr · 10-06-2009, 10:25 AM

check your vac lines for very small cracks before you take it in. Thats what fixed mine after 2 shops wanted to rpl comp,etc.Do a search and see what others have done to fix

K Man · 10-06-2009, 11:08 AM

JDSR: Thank you - I will do that. Hopefully, I am able to locate the problem before the shop is.

roadwalt · 10-06-2009, 08:18 PM

I had the same problem with my 03 Kountry Star. You can check the Evans valve with a pair of Vice Grips. Just squeeze the hose, try the AC if cool than the valve is sticking open. I used a large door hinge 6" and bolted it shut until the replacement valve showed up. The new valve has been working since (Knock on wood) but some have changed it several times. Good luck

K Man · 10-06-2009, 09:08 PM

Thanks, roadwalt. I will try that. I still have not had a chance to go to the unit. I have to locate this Evans valve. The picture from 007 will help for sure.

edgray · 10-06-2009, 09:19 PM

K Man: Just to be clear. In 007's picture the Evans valve is the one in the upper left corner. The hose clamps bolt heads look golden in Roger's picture. Evans is not the ball valve he installed in the lower hose. Good luck in you search. ED

K Man · 10-06-2009, 09:44 PM

Excellent - thanks, Edgray. I will get to the unit tomorrow for sure. I want to be reasonably sure this is the problem before the shop gets a crack at it. They are not a true motorhome shop. They are really a truck centre that is qualified to do Workhorse work. I am not real certain what they will know about AC work on motorhomes.

K Man · 10-06-2009, 10:26 PM

This may be helpful to other people with the same problem. I found the Evans home page. They have a complete listing of all their dash systems with troubleshooting and fix-it guides.
Here is the URL: Evans Tempcon, Inc