Dometic roof air conditioner Fan Motor problem on heat pump

[rbguinn]

Have you had this problem with this air conditioner and what fixed the problem?
In our 2003 Alpine Coach we have two Dometic® Duo-Therm Penguin- two-zone dual AC/dual 15,000 btu, w/integrated heat pumps, Model# 630516.321.
The rear air conditioner fan motor would not run on auto or low when on cool. I purchased and installed the capacitor #3100236.235 that I now discovered is for helping start the compressor….however the fan works fine on (auto, high, & low) when I set it to cool.
When I change the setting to heat via the heat pump, the same problem occurs as it did before where the fan settings for (auto & low)…the fan will not start & run. The fan works great when set to high when set on heat pump. I am considering buying & installing the Dometic conversion Mother Board- 3311557.000 for 630 models, and the Capacitor, Fan/Run 3100248.602.
What will fix our heat pump fan problem?? Thank you for your input!!

[Jmac00]

Originally Posted by rbguinn

Have you had this problem with this air conditioner and what fixed the problem?
In our 2003 Alpine Coach we have two Dometic® Duo-Therm Penguin- two-zone dual AC/dual 15,000 btu, w/integrated heat pumps, Model# 630516.321.
The rear air conditioner fan motor would not run on auto or low when on cool. I purchased and installed the capacitor #3100236.235 that I now discovered is for helping start the compressor….however the fan works fine on (auto, high, & low) when I set it to cool.
When I change the setting to heat via the heat pump, the same problem occurs as it did before where the fan settings for (auto & low)…the fan will not start & run. The fan works great when set to high when set on heat pump. I am considering buying & installing the Dometic conversion Mother Board- 3311557.000 for 630 models, and the Capacitor, Fan/Run 3100248.602.
What will fix our heat pump fan problem?? Thank you for your input!!

I would try a new thermostat before spending money on a circuit board, go with the easy and cheap stuff first

[bcbowers]

FWIW ... I had the exact situation occur on our rear AC. My son found a connectorized wire (wire with a push on connector) loose on the control board. We squeezed the connector with pliers to make it tighter and that fixed it It's worth a shot before spending that mountain of money on a new unit.

[rbguinn]

Originally Posted by bcbowers

FWIW ... I had the exact situation occur on our rear AC. My son found a connectorized wire (wire with a push on connector) loose on the control board. We squeezed the connector with pliers to make it tighter and that fixed it It's worth a shot before spending that mountain of money on a new unit.

Thank you for the great suggestion!! We are on the road & will be home in about two weeks. Will report outcome once I check for loose connectors.
Have experienced loose connections in our electrical system in the breaker box on the neutrals heating up cooking off insulation. I loosen then tighten each electrical screw connection once per year. If I don't loosen first, I can not establish if a screw has ceased from over heating.

[rbguinn]

I opened up the air conditioner looking for a loose connector on the mother board as you suggested. What I found was along this idea. I found on the mother board a loose connector of three that was not pushed in fully until the side clip locked it in place. Each of the connectors were different colors & I have no clue what their purpose is.

When I installed the new capacitor I must have hit the clip on the connector & the connector was no longer properly plugged in.

That did the trick & the fan motor now works on automatic as well as low when running the system as a heat exchanger. I was ready to spend $200+ dollars for a new mother board & 2nd capacitor if your suggestion did not fix the problem.

THANK YOU!!