Re: (ET) No main motor

["Jim Coate" <lists freerangeelectric com>]

Yup, classic symptoms of a lost field. Can also occur in late models when
one of the diodes on the little diode-varistor board goes bad. Typically
only a problem in forwards OR in reverse (requires two diodes to go bad to
kill both forwards AND reverse). Often can visually see the diode broken
in half, but sometimes a hairline crack at most so hard to see. Replace
the board as a complete assembly or if replacing the individual diode,
replace all the diodes and the varistor while there. Less likely, but for
both early or late models a bad connection anywhere going to the field
will of course have the same symptoms.

As David suggests, disconnect one cable to the armature, put in neutral,
and measure voltage across the field.

Jim Coate
www.ElectricTractorStore.com


>       Early E-15 with Field Reversing? I suspect you need another
> Reversing Relay. High mortality rate item, and when there is no field
> voltage, armature current goes through the roof and things get hot FAST!
>
> On 6/10/2012 8:05 PM, John Rieffel wrote:
>> Power cut out today in the middle of a regular mowing run. When I move
>> the speed control forward, the fuel gauge bottoms out, the usage meter
>> shoots up and things start smelling toasty.