2002 Patriot Dash AC

[Jack W Hannah]

I have my coach in the shop for dash AC work and their diagnosis is pointing towards a faulty Control Head.

I have an inquiry in to BCS for a replacement Head Control Unit but haven't heard back.

Has anyone replaced their Dash AC Head Control Unit in a Beaver Coach of this vintage? If so, can you share w/me the source or part no. for a replacement?

Thank you

[Steve Huber Co-Admin]

Jack,
I don't know the part number but it is probably a GM unit from that vintage. Since it is vacuum operated, make sure the shop has verified the vacuum pump is functional and that there are no cracked/ broken vacuum lines running to it. Control units are available at most auto parts stores for less than $200.
Steve

[Eric Maclean]

Jack
As Steve has pointed out the control head is likely a GM part.
I don't know if your 2002 is the same as my 1997 unit but I'm betting it is mine has a GM control head model#16208521
GM part used in a 1995 to 97 Chevy Cavalier without rear defrost.
Looks like this
https://www.ebay.com/itm/125132239450

Before you go out checking the local wrecking yards
Is it theater control that is not working the Bowden cable if so the problem is likely repairable if you remove the control from the dash you will see where the rotary knob turns a barrel shaped cylinder with a helix grove in it the cable is connected to a pin which travels in that grove the pin can jump out of the groove and the cable won't work.
If your cable isn't moving when the knob is rotated take the dash unit out of the dash far enough to local and remove the cover from over the barrel and inspect the pin placement if it's out of place simply put it back into the slot and reinstall the cover.
You may want to lube the cable as well.

Hope this helps
Eric

[Fred Cook]

My dash AC does not work either. I chose not to repair it as it doesn’t do much to cool down the coach. Instead I turn on the generator and then turn on the roof AC’s to cool the coach down while traveling. It works very well.

[Fred Brooks]

     Fred,
  Here is a consideration. Normally in a car, the air conditioner will eventually overcome the volume of air in the cabin. Dash air conditioners normally will cool the ambient air temperature 25 to 30 degrees when on "max". The issue in an RV is you are blowing cold air off into infinity. If you try hanging a sheet or curtain across behind the captain's chairs, it will trap and recirculate the cool air over and over. Cindy and I have been doing this for over 20 years and it works. Hope this helps, Fred

[Eric Maclean]

Jack
On the Acme air system the temperature is not controlled by a blend door as is it is in most cards and trucks where the air is deverted through either the heater core or the evaporator instead the air is blown through both the heater core and the evaporator before it enters the cabin .
In order to get cold air you have to stop putting hot water into the heater core and cool the evaporator with refrigerant
In these systems the biggest cause for poor cooling in a properly charged system is that the hot water control valve does not close all the way and the heater core continues to heat the air as the evaporator is trying to cool it causing poor cooling .
Luckily this is easy to check simply clamp off the hoses going to the heater core and see if the A/C seems to get colder if it does the hot water control valve is not closing completely ( this is a very common problem)
As Fred has pointed out the dash system is fighting an up hill battle at the best of times it makes sense to get the most out of the system by not having it work against itself.

Hope this helps
Eric