Dash Board A/C Not Cooling

[fagnaml]

Yesterday I drove my 2007 Damon Astoria from the RV storage facility to my home to give it a bath this coming weekend's outing to Austin (for  three days away from the stressful oil and gas business!).  During that 20 minute drive, the dash board A/C only blew hot air (it was 101 F in Katy, TX yesterday).   The fan for the A/C compressor discharge condenser (some call it the evaporator condenser) was running so the system presumably had some Freon (134a type).  I purchased a couple of cans of Freon, gauge, etc. from my local Walmart.   Upon attaching the first can to the A/C low pressure port, the gauge showed only 10 psi meaning the system was quite low on Freon.  After adding 40 ounces of Freon to the 56 ounce system, the gauge came into range at 40 psi.  A full charge of Freon only had a minor affect on the dash board air as it was still very warm.   The low pressure tube leaving the evaporator coil was not as cool to the touch as I would have expected.  I'm wondering if the expansion valve is stuck closed?  Or are there other reasons for no cool air?   If there's no easy fix one evening this week I presume I can run the roof A/Cs for the short two hour drive to Austin (correct?). 

Thanks for your thoughts and guidance!

[wolfe10]

Mike,

Yes, run the generator and roof A/C's.  Even if the dash A/C is working perfectly, it will not keep up with 100 degree exterior temperature.

[jbrunson]

standard practice for me... it will take the whole 2 hours to cool off so plug in the night before departure and cool the coach down with roof ac.... i also run a small fan placed on the dash pointed at driver.... another pound of R-134 might get the system going... you have came this far... it was on sale for $4.99 a can at Walmart last week.

[jbrunson]

http://www.evanstempcon.com/index.php

 

possible parts source

[dave111451]

You are aware those are only 12 ounce cans. add another can or get a dual gauge set hooked up so you can read high side pressure also and we can give you more help and direction.  hope this helps      dave

[dickandlois]

4 hours ago, fagnaml said:

Yesterday I drove my 2007 Damon Astoria from the RV storage facility to my home to give it a bath this coming weekend's outing to Austin (for  three days away from the stressful oil and gas business!).  During that 20 minute drive, the dash board A/C only blew hot air (it was 101 F in Katy, TX yesterday).   The fan for the A/C compressor discharge condenser (some call it the evaporator condenser) was running so the system presumably had some Freon (134a type).  I purchased a couple of cans of Freon, gauge, etc. from my local Walmart.   Upon attaching the first can to the A/C low pressure port, the gauge showed only 10 psi meaning the system was quite low on Freon.  After adding 40 ounces of Freon to the 56 ounce system, the gauge came into range at 40 psi.  A full charge of Freon only had a minor affect on the dash board air as it was still very warm.   The low pressure tube leaving the evaporator coil was not as cool to the touch as I would have expected.  I'm wondering if the expansion valve is stuck closed?  Or are there other reasons for no cool air?   If there's no easy fix one evening this week I presume I can run the roof A/Cs for the short two hour drive to Austin (correct?). 

Thanks for your thoughts and guidance!

As mentioned indirectly by Dave. One can over charge a system and a set of manifold gauges that read the low and high side of the system is always the best method when charging.

Using only the low side - gauge attached to the system - you might try to turn the system on and off and watch the gauge. Having a helper inside to turn the system on and off helps.. The gauge should read higher when off and drop as the system starts. Not All Those do it your self gauges are created equal and to much 134 can be bad also!!

Do you have access to the field truck  mechanics?

Rich. 

[wayne77590]

The thermostat control uses a vacuum type pump to open and close the AC/Heater door. If there is a crack in the line or "other" it can cause warm air to come in. It is usually located under the front "hood" and looks just like an old time windshield wiper vacuum. There should be one line going to it, usually green but could be read.  Check for any vacuum leaks. Cheap fix if found.

 

[rsbilledwards]

As was commented on earlier, dash will cool dash area only. We put up a curtain just back of the front seats to contain both the cool and warm from the dash. It works marvelously, even better after Janet installed some rare earth magnets to keep the two sides together.

 

Bill Edwards