Newmar Dutch Star Diesel Freightliner Chassis Dash A/C

[ronaldbrinley]

I have a 2000 Dutch Star Motorhome built on a Freightliner Raised Rail Chassis. The Dash A/C does not work. Blows hot air after engine warm up. The Vent function blows Hot air as well. Currently running generator and roof air while traveling. Having trouble getting someone to work on coach. They say they can not work on older coach than 2013. Any suggestions would be greatly appreciated.

[elkhartjim]

I'm curious who "they" are!  

 

[rayin]

First, this dash air system is nothing special, any automotive A/C shop can work on it, but the sheer size of a MH might intimidate some techs. Without knowing the brand of your A/C system all I can do it speculate.

The first thing to do is determine if the water valve to the heater core is operating as designed. When you have the heater running the hose on both sides of the water valve should feel hot/warm. When the A/C is running the outlet side of the water valve hose should not feel warm. It is does the water valve is defective. If it does not feel warm, the next step is to determine if the compressor is running.

When the compressor is running both the belt pulley and the inside of the pulley will be spinning. If the inside is not spinning the refrigerant level must be checked. Instead of writing a book, I'll now refer you to this very complete  Heavy Duty Air Conditioning Service Manual,  which does address long refrigerant hoses found on MH's.

If your A/C system is an Evans TempCon,(ProAirlic.com)) they filed bankruptcy a few months ago. As a result their website is down, but parts are available from other suppliers.

This is all my bookmarks for a 12V A/C system, including all brands I have found on the internet:

 12V air conditioning
https://www.btrac.com/documents/svc-manual-revision-i-feb-2011.pdf
https://coldhose.com/
https://www.nwrvsupply.com/category/05-03.html
https://www.proairllc.com/design-engineering/evans-tempcon-guides/
http://www.cdr-roc.com/RSF/RV-CAR/Travel Supreme/Spartan & chassis info/EVANS Dash HVAC_System_Service_Manual.pdf
https://www.comfortairgr.com/product-category/evans-tempcon-motorome-rv-parts/
https://www.comfortairgr.com/product-category/evans-tempcon-motorome-rv-parts/
https://newpar.newmarcorp.com/instance1Env99NEWMAR/html/images/SS2013EVEQUILTRAIN.pdf
https://www.rvtechmag.com/tech/51_r134.php
https://rvcoolingunit.com/Default.aspx
https://www.comfortairgr.com/product-category/scs-victory-climate-systems/
https://library.densoassets.com/m/155322b79fcb708a/original/RV-HVAC-Service-Manual.pdf
http://soldbyrichard.com/rvacheaterparts.php
http://acmeairparts.com/rvacheaterparts.html
https://www.amazon.com/nextzett-96110515-Klima-Cleaner-Conditioner-Cleaner/dp/B0002Z2MKO
https://www.winnebago.com/Files/Files/Winnebago/Resources/Service/2016-01 Evans Tempcon Auto Air Conditioning.pdf
https://www.comfortairgr.com/rv-hvac-downloads/

Edited January 17, 2023 by rayin

[wildebill308]

I agree with Ray. It sounds like the water valve to the heater core is not working correctly and low on refrigerant. 

Where are you located?

Bill

[elibedarn]

I had that issue as well. I added a manual inline off valve to stop hot water flow into the heater core.  

[bestred1]

My suggestion would be to look for someone in your area that has worked on a Bus A/C system. There can be differences in the operating parameters for these systems as I recently learned on my Evans-Tempcon system in a 2011 Coachman. I previously posted my repair experience as I was misled by folks that work on auto systems. The suction side pressure is designed to operate considerably lower on my system as compared any auto A/C. This gave me issues for many months.

 

You made no mention about the A/C compressor cycling on & off. Pretty hard to give any repair advice other than what has already been responded.

[johnbro]

I’ve read the valves fail. A manual in IDD vakve is an easy and cheap fix. 

[billieb72]

We had the same issue in our DS4023DP and bought the can of refrigerant at Walmart and it worked.  

[wwwarren2]

I had similar issue on my 2005. Would blow cold until it warmed up. my issue was cooling fan not blowing. blown fuse. You should be able to hear fan kick on when you turn on.