No Max-AC

The "Max" setting may also invoke "HIGH" fan speed on many A/C's but the major difference is it closes the outside air intake so the sound of air rushing into the unit INSIDE gets louder. No difference in air flow, well.. possibly a slight reduction.

tmmar wrote:
Yes, it is the dash AC and I do not notice any difference when turning the switch from the AC setting to the max AC setting. On my '08 coach I did hear a louder fan when on max AC as compared to the normal AC setting. I will check with others who have the same coach to see if they notice any difference in loudness on max
AC.

If you had the 2008 Berkshire, the noise you heard was not the fan speed increasing. It was the perception caused by the outside intake door closing and the fan had to work harder and the pitch changed. Doug

tmmar wrote:
Yes, it is the dash AC and I do not notice any difference when turning the switch from the AC setting to the max AC setting. On my '08 coach I did hear a louder fan when on max AC as compared to the normal AC setting. I will check with others who have the same coach to see if they notice any difference in loudness on max
AC.

Brand and Model of your 2008 Coach please. Doug

Yes, it is the dash AC and I do not notice any difference when turning the switch from the AC setting to the max AC setting. On my '08 coach I did hear a louder fan when on max AC as compared to the normal AC setting. I will check with others who have the same coach to see if they notice any difference in loudness on max
AC.

I've always said that you're never too old to learn something and I did today, since I never gave much thought to this fan speed thing. However with my F150, running on low speed and then pushing the max air button it does run wide open until you manually lower the speed again.

Normal air sucks in a mixture of recirculated air (From inside the cab) and outside air.. this is normally the best option.

MAX air, on a motor home is generally useless, closes the outside air intake and sucks air only from the cab inlet.. On most cars you hear this as an increase in noise which you assume means an increase in fan speed, it does not. there is no increase in fan speed.. It is simply an increase in vortex noise at the air inlet.

On a motor home the cab air inlet is often much larger and does not produce vortex noise,, On mine it is nearly a square foot of gridwork.

garry1p wrote:
The fan speed does not change from hi speed what happens is the noise becomes louder since you are pulling the air from inside.

x2

The fan speed does not change from hi speed what happens is the noise becomes louder since you are pulling the air from inside.

Freightliner does NOT install the dash controls, only the compressor/condenser and the coolant lines. ALL the rest of the AC system is the OEM builder. NEVER take a Class A motorhome to the chassis builder for a Dash AC problem if under warranty by the OEM. 99% of Class A dash AC problems are caused by the RV buider and NOT the chassis builder. IF you take it to Freightliner first and they determine it is a Coach OEM problem, YOU will have to pay the diagnostic fee, and believe me, Freightliner will NOT waive any check out fee. Which is usually $150 to $250. Call your RV dealer first to ask what you should do and who to take it too. Doug

Class A motorhomes do NOT change fan speed on Max setting. ALL the MAX setting does is close the fresh air door and you recirculate the interior air, which will yield COLDER air, hence the Max description. Been this way for over 30 years. Doug