(ET) Sparks are never good on a tractor

[Chris Zach <czach computer org>]

So I was mowing all afternoon with the E20. Went forward into a bit of 
brush, threw the tractor in reverse and all hell broke loose.

First, the mower deck started to spark. Also the tractor was not moving 
and all of my "battery low" indicators came on. Bad. Shut down, 
everything stopped.

Fired up the tractor, as soon as I pushed down on the throttle nothing 
moved, sparks on the deck, even with the PTO off. Great, looks like a 
ground fault somewhere. Probably on the deck and motor circuit. Fun.

Unplugged the deck. No more sparks. Good. IN neutral the motor would run 
fine forward, would barely turn reverse with the battery low lights on 
*FULL* bright. Opened up the relays, tapped a few, reverse came back. 
Looks like one of my field relays is loose or something in reverse; will 
have to look into this since the field should not be affected by the 
FWD-REV switch.

Fortunately I was done, but it looks like I'll be chasing down a couple 
of shorts this weekend. On the longer term, I'd rather replace the push 
pull contactors than swap them; anyone have a spare set?

Chris