[Richard]

Forest,

On my coach, the relay that switches back and forth between Air Con and 220 Aquahot is located just below the fuse panel in the closet. It's a big un. I say that because I can hear it click when I flip the AC/AH switch at the oven panel.

[Richard]

The function of the two black relay cubes is now clear. The aquahot wants a 12 ground at it's terminal input strip to activate a zone. The PSC thermostats above the passenger and in the bedroom provide a 12+ signal. So what Newell did was use the 12V+ signal from the tstat to activate the relay. The contacts in the relay when closed, ground the signal. It's a little funky because the same color wire is used in and out of the relay. It isn't obvious what is happening until you match the wires on the relay to the function of the relay terminals.

When the tsat signal is now grounded to the living room input terminal, 12V positive now is present on the output side of the zone 1, topmost, clear relay cube mounted on the AH panel.

[Latitude 28]

Richard 
Thanks for your phone call and checking out your coach to compare systems and what might be going on with our system.  Your help was spot on!

Others have described their systems and the fans correlation with each otherWe are up and running with the AHworking correctly.  I think we originally had a stuck relay due to the bad AH couch fan.  Trouble shooting the toe kick fan (continuously running) led me to those black cubed relays, as disconnecting the ground wire stopped the toe kick fan.  Messing around with those relays I apparently connected the 12v tsat lead backwards which compounded the problem.  You figured out what was really going on and why the black relays are there. 

Also, thanks to all who responded as it really helped me understand how this system is supposed to work!

Steve Denton

[pairodice]

Were you able to get the FRONT driver/passenger side vents to output heat? Our coach is putting out heat in the kitchen toe kick fan and now the bedroom toe kick fan but nothing from the front of the coach; maybe that is what the middle clear relay controls, not sure. Have to get a new clear relay then can turn it all on (after the sun goes down!)...

[rheavn]

"Our coach is putting out heat in the kitchen toe kick fan and now the bedroom toe kick fan but nothing from the front of the coach; maybe that is what the middle clear relay controls, not sure. Have to get a new clear relay then can turn it all on"

I think you are looking for your problem in the wrong place.  The kitchen and salon blowers come on together.  Since your kitchen is blowing heat, you need to check the heat exchanger that provides heat to the salon & front.  The motors are known for failing.  I am on blower #3.  Sometimes the front heat exchanger is under the drivers side sofa and sometimes behind a wall in basement bay L-3.

[Latitude 28]

Yes, we have heat blowing from the couch fan:-) The original problem we had was the blower under the couch was not working in the Hi-Low or Tstat mode. Found the blower motor very stiff when I tried to rotate it by hand. So removed and replace the blower motor (Auto Zone P/N PM393 lifetime guarantee...credit to the gurus for finding P/N). So now it works on the Hi-Lo switch and noticed the toe kick fan running constantly with no way of controlling it....I could shut it off by pulling the ground off of the top small black cube relay at the Aqua Hot. Richard spent the day looking at his coach's black relays to figure out what they do. Some troubleshooting and correcting my SIPs ("self induced problems") i.e. wires swapped on the wrong terminals we have heat! The toe kick fan and front blower come on together.

The top clear relay goes to the forward AH zone pump for the front of the coach....the middle clear relay goes to the middle zone pump and heats the water bay zone....the bottom clear relay goes to the bedroom zone pump in the aft position....possibly the bathrooms not completely sure on that one. I would agree with Steve Bare your probably looking at the front blower motor having an issue.

Wanted to add; Someone, doing previous trouble shooting of the blower motor, had swapped the small black cube relays at the Aqua Hot. One of them may have been stuck closed. My jostling them around opened it up as they checked good when I put the meter to them. They are working as they should now!
Steve Denton

[DK on the road]

So That I understand, The HI-LO switch is suppose to control the front salon/toe kick fan ?

I found the that fan had quite working and diagnosed a temperature sensor that is just before the power to the heating element had fail, no continuity across the sensor. I replaced it with a unit from and appliance supply house that is rated at 260 deg vs the factory 270 sensor. I have never had anything but 1 speed from that fan and I cannot find out what the switch make speed up or down. By the way, that heating element and fan are all electric and have no AH system running to it . My kitchen toe kick is AH and works great and the back of the coach works great including the 1/2 bath.

Also I have intermittent heat out of my AH heater next to my drivers seat, my whisper heat. I have opened it up, cleaned up all. I get fan, no problem, but heat is sometimes, and I don't know why. Help