3720 Heater Repair

[Scarborough]

To those if you who are as unfortunate as myself here is my issue.
Water collects in the tray under left and right blowers. It freezes and blows the resistor in the heater housing you are lucky, if you are unlucky it burns out the fan motor. John Deere only sells the complete blower fan with the resistor. Expensive! BUT the resistor is available separately from Bobcat. I'm going to upload a few pictures in the hope of helping others save on the repair. In one of the pictures you can see some pooled water. It gets to be about 3/4" deep then when the temperature drops it freezes the fan cage and that is what burns out everything. I plan on drilling a couple of holes through the base tray I know the water will drop on the glass in the summer with the AC on.

 

[TractorTech]

Old forum on the motors and resistor
Motor and resistor used on many ststems. Aftermarket available from AP Air and others.

https://www.tractorbynet.com/forums/threads/john-deere-4720-blower-motor-resistor-pack-75-75-216-22.445675/

 

[williambaird]

Hey man, this is a common issue on the JD 3720 cab tractors – AC condensate water collects in the tray under the left and right blowers. In cold weather it freezes, and the fan motor runs while it's locked up, burning out the resistor.

Quick fix: Drill a couple of small holes (around 3/4" or smaller) in the bottom of the base tray so the water can drain out. In summer with the AC on, it'll just drip onto the grass – no big deal.

The good news is the resistor is available separately (a lot of guys use the cheaper Bobcat-compatible one instead of buying the expensive full blower assembly from Deere).

Waiting for your pictures – they'll definitely help others! Good luck with the repair.