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Re: (ET) Need diagnositic help on E12

         After moving the throttle to either position, 'F' or 'R', do you hear any contactors pulling in? If you advance the throttle further, do you hear any of the armature resistor bypass contactors pick up?
         While you are doing either of these checks, observe the 'Power Use' gauge. Does it move? If not, the armature is not drawing current.The double contactors are prime suspects. Check for armature voltage at the traction motor. There probably isn't any. {Use a low impedance VOM, not a sand based unit.}
 
----- Original Message -----
Sent: Tuesday, March 15, 2005 12:51 PM
Subject: (ET) Need diagnositic help on E12

Hi Guys,
<>E-12 went dead again after going only 15 feet in the last snowfall.  Snowthrower still works but no forward or reverse on the tractor.
This is what has been checked so far:

Both relays close when the key and seat switch are closed (Normal operating Condition NOC).  Between the two contacts on top of each, 1RTN had 41.0v and 2RTN had 40.9v. They both stayed closed in both Forward and Reverse.
Then checked between wires # 11 and #14 and got 39.7v in Forward.
Then checked between wires # 11 and #41 and got 39.7v in Reverse.
Then checked between wires #8 and #24 and got 39.7 in both Forward and Reverse.
This tractor has had some uneven power in both Forward and Reverse since I bought it 2 years ago . That is, the power felt a bit uneven and the power needle would sway a little back and forth.  It did stop dead another time when the insulation on one of the wires from the Varistor got stripped accidentally (when I was reinstalling the speed control) and this wire probably touched something else.  Have covered the badly insulated spot.

Tested between wires #8 and #7 and got 38.9v in Forward and 38.7v in Reverse.   Got similar results between #8 and #6.  That is 39.7 in Forward and 38.6 in Reverse.
Pulled up the cover over the battery charger and inspected the heavy ribbon resistors.  They looked fine front and back and so did all the connections.  I remember that they heated up like a toaster back when I had the Varistor problem but they look fine now.
Then checked the main connection posts on the motor and they seemed fine. 

<>Got 39.3v across the large connection posts in both in Forward and Reverse and.  Had this motor rebuilt with new bearings and brushes less than a year ago.  Would hope it is still good.
Rotated the motor by hand but no action.  Found wire #22 on the seat switch and wire# 62 on the Varistor assembly.  There are 38.6v between them in Forward. 

As to current, there is some slight current usage but nothing like when the toaster was happening. 
I am just guessing but could I have burned something out or have a bad connection somewhere on the Varistor assembly, a diode or resistor or something like that??? 

Would appreciate any knowledge you can share,
Thanks,
Richard "Zack" Zachary
E12  model 26AE12CA serial # FP22038

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