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Loganhorse's avatar
Loganhorse
Explorer
Jan 03, 2021

Atwood 7920II blower not coming on

Blower isn't coming on, and led starts flashing one time. I checked voltage to the motor when I get a click no voltage but have voltage on the red wire below it. I think the control board is the issue can someone confirm?

5 Replies

  • What do you have to lose.......it ain't working now so if it gets messed up you would need a new board anyway

    Heat up that Iron and give it a try
  • Old-Biscuit wrote:
    Sure.........
    If you know how to solder and know/find the relay

    I located the relay. Switch was open then when I jumped the blower out it made. Would I be better to replace the whole board or is it safe to say the relay is probably the issue? Soldering is no problem.
  • Old-Biscuit wrote:
    DC+ from a fused source goes to circuit board 'PWR' connection
    *also the source of the DC+ to thermostat

    When thermostat closes that DC+ comes back and goes to circuit board multi-pin connector
    *also goes to Sail Switch

    When circuit board gets that DC+ from the thermostat it sends DC+ to Fan Motor from the 'BLO' connection on circuit board

    Got DC+ to 'PWR' on Red Wire
    Get DC+ on Blue Wire at the multi-pin connection
    No DC+ on Red Wire from 'BLO' to Motor
    *Could be Circuit Board
    *Could also be Sail Switch stuck Closed...Circuit board will not allow fan operation if Sail Switch is Closed BEFORE Fan runs

    ***Link Removed***


    I will chech the sail switch when I get home from work. If the circuit board is bad, can one replace the relay on it instead of the whole board since I figure that's what is bad?
  • DC+ from a fused source goes to circuit board 'PWR' connection
    *also the source of the DC+ to thermostat

    When thermostat closes that DC+ comes back and goes to circuit board multi-pin connector
    *also goes to Sail Switch

    When circuit board gets that DC+ from the thermostat it sends DC+ to Fan Motor from the 'BLO' connection on circuit board

    Got DC+ to 'PWR' on Red Wire
    Get DC+ on Blue Wire at the multi-pin connection
    No DC+ on Red Wire from 'BLO' to Motor
    *Could be Circuit Board
    *Could also be Sail Switch stuck Closed...Circuit board will not allow fan operation if Sail Switch is Closed BEFORE Fan runs

    See pg 4 for wiring diagram