Dometic 57915.531 Air Conditioner Blows 3 amp fuse in control box

Steve,

The three amp fuse is installed in the board to protect from shorts or overloads created by disconnecting or reconnecting components when DC power is still connected to the system. If the fuse is blowing, then you more than likely have a short in the 12VDC system between the control unit and the thermostat.

1. Pull the cover off of thermostat and remove the +12 (or +7.5 depending on the model) wire. Access the other end of the wire in the AC compartment. Using an ohmmeter, touch the end of the wire at the AC with one lead and touch the control box with the other (or any ground source). If you get a reading other than OL or Infinity, then that wire is shorted out in the wall somewhere. If not, repeat the steps for the rest of wires except the ground of course. If all of these wires appear to be fine, you may need to take it in for some more extensive troubleshooting.

Hope this helps,

Jeff

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