John Deere Electric 90 - Service Manual and Repair Question

bryanannas

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  • / John Deere Electric 90 - Service Manual and Repair Question
Hello forum.

I've been using a John Deer Electric 90 for the past 7-8 years (bought it for 150$ off CL with new batteries from Walmart), no issues at all until this afternoon. I noticed an electrical smell, at first I thought it was coming from a truck that was passing by, but when the blades started to lose power, and I looked down and saw some smoke, I knew it was coming from the tractor.

My current thinking is that one of the blade motors burned up. They are from the early 1970s, so that would make sense.

There was a loose connection to a motor terminal and some of the wiring looked melted so I replaced the wiring to the motor I thought was bad... no dice. Neither motor spins up when I turn on the blades.

The drive motor works just fine, it drives no prob, just don't have blades.

Questions... considering I'm going to go down the path of fixing the mower. I don't want to spend a few hundred dollars on a new riding mower, I also love this mower, it's been a gem for the past 8 years and I don't want to stop now.

1) Does anybody have or know where I can find a service manual (in .PDF ideally) so I can avoid having to pay $20 and wait for a hard copy from Ebay, I need to get this thing back up and running ASAP.

I'm wondering if it's possible that the motors are good and some mechanical relay, or something between the battery, the power switch and the motors is a problem. They operate at a fixed speed, no speed control.

I'd hate to replace the motors and later find out it was not a motor problem at all. The electrical smell was bad, still is bad in proximity, someone with more experience could probably tell just by smell if it was a motor or something else.

2) Does anybody know of a replacement motor option? I can try and find one used but... my preference would be to buy a new replacement, or buy something I could make work.

3) Can anyone explain why these motors have 3 wires? I'm familiar with brushed DC motors with a positive and negative and BLDC with 3 leads, but these motors have 3 wires and I don't know exactly why. Maybe a service manual will help.

If you have any ideas or know someone who does, please let me know!

I'm going to fix this thing so I'll post an update when I get it sorted out. I may end up just taking everything apart and going through each bit, may be faster than everything else.
 

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bryanannas

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  • / John Deere Electric 90 - Service Manual and Repair Question
Any ideas on how to test out the motor?
 
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