Dash a/c not cool enough...

[DoubleVeteran]

Hi all,

I have a 2002 Phaeton DP, and the dash air has never been cold...only mildly cool. I know that is subjective, but for a comparison, the a/c in my 2009 Ford F-150 runs twice as cool as the Phaeton under the same conditions; highway speeds @ 85 degrees.

I had it checked at two different RV service centers and both said the air was working properly. I know I can run the genny and roof-top a/c, but I'm thinking the dash a/c should work much better. Is this typical of DP coaches to have marginal dash a/c cooling?

Thnx,
Larry

[DSDP_Don]

Larry....When we traveled in the summer months in our Diplomat, I was not a big fan of running the generator and roof A/C all day. We use to use a spring loaded shower rod and a clear shower curtain that we put up right behind the front seats. You could still see in the back and the split in the curtain allowed easy access. Obviously, it's not a good idea if you have pets or people riding in the back.

It kept the front cool until about 3:00 pm and then we would turn on the roof A/C because we were usually ready to stop for the evening.

[KilroyGuy]

It also helps to cool the smallest space available --- try closing the bedroom and/or bathroom door.

[gsander1]

mike brez wrote:
Our dash and over the road air cool the whole coach fairly well.

That's because you have a Magna my friend.

One of the main benefits to owning the Country Coach Magna or Affinity is that the chassis A/C system has two evaporators. Dash evaporator is as much as 19K BTU depending on year. And bedroom evaporator is 13.5K BTU. I have yet to run generator and roof A/C on my coach and I live in hot, humid Birmingham, Alabama.

[Golden_HVAC]

If you think about it, the dash air will cool off a 6 foot wide and 6 foot deep cab area of the F-150 really well. But the cab of the DP is 8'6" wide, larger glass area, and upwards of 30' long! So running the generator on a warm day is somewhat a requirement, as the dash air can only do so much.

Good luck!

Fred.

[Mr_Mark1]

We had the air in our '08 Dynasty start blowing warm several times during the early years of ownership. After three attempts at Colton Truck Terminal in Colton, CA, the fixes didn't last long (waste of money). They just didn't know what they were doing and throwing parts at it.

So, I was so lucky to find Redlands Performance and RV repair in Redlands, CA. They fixed it right the first time. It ran cold for a solid three years until we sold it on consignment last fall.

We could run just the dash air until the outside temp was about 95 (for a couple of hours) then I would turn on the roof airs. Any outside temps at 90 or below, we were good with the dash air.

I never measured the temp out of the vents but when I put my hand up to the vent, the air felt ice cold coming out. The vast area at the front of a motorhome does make a difference but the air coming out of the vents should feel very cold.

Good luck,
MM.

[Cobra21]

The dash air is to be about 20 degrees cooler the the ambient temp. inside.
So if it is 90 in the coach, then it should blow about 70. It will work its
way down as the inside temp keeps falling. Same goes for the roof top unit.
When it is 70 inside, the unit should blow around 50. When they run like this they are also pulling the humidity out which is the big thing!

Hope this helps, Brian

P.S. Some units just will not cool well depending on the sun, glass, insulation, and air leaks or quality of the build.

[lj2654]

I had my dash A/C repaired 2 years ago due to a leaking line. Air was a lot cooler after the repair. 6 months later not as cold.

I decided it was wasting my money, so now I use the dash air early in the am, then run the generator and roof a/c's late morning and afternoon.

[mike_brez]

Our dash and over the road air cool the whole coach fairly well.

[wa8yxm]

The Dash Air is designed for the cabin of a truck, Say an F-350 Ford

No way can it properly cool an entire

Two choices

1: There are companies that make an insulating curtain that goes just behind the front seats segregating the cockpit from the rest of the house.

Two... Help it along a bit by firing up ye-old Generator and activating ROOF AIR.

[dougrainer]

midnightsadie wrote:
stick a temp gauge in the vent ,should read 42deg if its much from that its not right.

WRONG. This may be true for Automotive and Pick Up trucks, but is NOT even close for a Class A Motorhome. The FACTORY specs for a Class A Motorhome is 60 degree output at the nearest vent to the evap core with ambient temp above 70 degrees. . That said, most Class A's will get below 60 and even down to 48 to 50 degrees in sub 95 temps. Below are the 2 links for the BEST diag of Motorhome Dash AC systems. Doug

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

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

[DoubleVeteran]

...and I'll be sure to check that heater valve...thnx again!

Larry

[jplante4]

Two class A motor homes and both had issues with the heater valve. That's where I'd start.

[Ivylog]

Once the engine is warm checking the outlet air temp is not going to tell you much as the heater may have hot water going through it. Checking the temp in the first couple minutes will. If the heater hoses in the dash are only warm it will be defeating the AC. Putting a manual shutoff valve in a line is the easiest solution if the electric motor is not shutting the water flow completely.
I rarely have to run the generator and roof ACs BUT I have a shutoff valve and I bypassed the defrosting relay so my compressor runs all the time. Taking the plug off of it and putting a fues in the plug is all it takes. In the East when the air flow decreases I shut the AC off for five minutes to let it melt the ice. Out West I rarely have to as the lower humidity takes longer to ice up.

[DoubleVeteran]

I was referring to the air outlet temp. I'll check the temp there.

Thnx all the the good advice!

Larry