[2BirdDogs]

Thanks for the tip Richard.  I swapped those relays around and I still don't get 12 volts at the fans.  I tested the fans and they do work.

I have noticed that the led in the #1 position of the 12v fuse panel in the rear closet is on and off randomly.  So does #21.  Do the leds commonly fail?  I have another place where it is not lit but I know the circuit is working.

On our 07 coach #3 and #6 toekick fans only run on AH when our main thermostat zone 1 (galley) and zone 3 (bedroom) are set to “gas heat”.

[dbld58]

Gordon,

Your memory and explanation are spot on.

The key point being, and I realize that I am repeating what you and Rudy said, that the relay is activated or the pump would not run. The next logical check is to put a voltmeter on terminals 4 and 6 to see if they have 12v. The fans are typically powered by either of these terminals as indicated by the manual in the link I posted.

If those terminals have 12v, then I would check the continuity between there and the terminals at the fan.

I checked voltage on terminals 4 & 6 at all three relays, and none of the three show 12v even though the galley works perfectly.  I can hear and feel the pumps working.  

I'm very frustrated.

[Trainer]

David, if a pump an/or fan coils are working, the related clear relay is conducting power, period. Your meter may not be reporting power correctly.

[Richard]

I am always doing sanity checks on myself. Because someone needs to check on my work………


When checking a voltage, I always try to check a known just to ensure I have the meter set correctly. In this case, put the pos probe on the big power lug coming into the AH for the sanity check. That will tell you if you have a good ground for the meter. Many times I have learned I did not have a good ground when checking DC voltage.

[folivier]

Good point Richard. I've also found that a wire can test with good (proper) voltage but when a load is put on it the voltage drops out. Either due to a bad ground/positive from corrosion or even a wire that is broken or corroded inside the insulation.
Is it possible to disconnect the wire from the fan and test the voltage like that?

[Parisjet]

Thanks Rudy.

I'm struggling with this because the bathroom, galley, and driver fans all work. 

The salon/living room heater is a toe-kick self contained electric cadet heater so it would not be a factor.

I'll fiddle around with the AH relays some more.  Does anyone have a diagram for the relay wire connections?  I hoped to see some common wire colors at the fans and at the relays but I didn't.  The wires feeding the fans are brown and blue if my memory serves me...I'll have to open that up again to verify.

You might try the #1 heat pump setting on the 4 zone thermostat (if that is the system that you have)
And set it as high as it goes. 

I set all of my zones to 90 degrees last night and for the first time since i owned the coach had the Galley AQH heater fan started working. Then working backward shutting off each zone one at a time found that the Galley fan was controlled by the #1 Thermostat on Heat Pump setting.

[dbld58]

Hope everyone had a great Thanksgiving!!

For a brief update, I've spoken to Rudy who instructed me on how to correctly check the output voltage at the relays.  I was not doing it correctly before.  All relays seem to be working as they should (darn - I was hoping one wasn't so it would be an easier fix).  I included a wiring diagram for future reference to anyone using this thread.

Tomorrow I will dig back into the unit and try replacing the fans even though I had tested them before.  I should have measured for sizing them so I could do it in one shot, but as it is, I need to get in there first, measure, then get the fans before reporting back.

Thank for the help everyone (especially Rudy for his thoughtfulness and time on the phone).

Aquahot wire diagram.pdf Size: 568.56 KB  Downloads: 28

[Parisjet]

Hope everyone had a great Thanksgiving!!

For a brief update, I've spoken to Rudy who instructed me on how to correctly check the output voltage at the relays.  I was not doing it correctly before.  All relays seem to be working as they should (darn - I was hoping one wasn't so it would be an easier fix).  I included a wiring diagram for future reference to anyone using this thread.

Tomorrow I will dig back into the unit and try replacing the fans even though I had tested them before.  I should have measured for sizing them so I could do it in one shot, but as it is, I need to get in there first, measure, then get the fans before reporting back.

Thank for the help everyone (especially Rudy for his thoughtfulness and time on the phone).

That diagram explains a lot of the questions i have, thanks for posting.