(ET) troubleshooting

[David C Robie <mycroftxx1 juno com>]

Models; all bigframe - Ie  12,215,16, 20

Symptom;  Turn key on, no relay clicks at all

Best connection of meter to get at both + and - of 36V  is the small
accessory socket under hood.  Strip a slice of insulation off each wire. 
Then you have both + and - 36 reference points

Most common problem - no 36 at all there,  a bad conn at one battery
jumper. 
   Another way to find this same problem;  plug in the charger turn it
on.  Start the tractor.  If tractor runs on charger but not on battery,
you have a battery jumper problem.  This is most apt to occur at 'first
mow of the season'.

Test lights and winch.  If both ok;

Test for 36 or more V at the accessory socket.  You could still have a
bad jumper (etc) in the frnt compartment or on one rear battery if
there's no 36 there.'
   Only  things other than battery jumpers between this socket and
battery pack are a fusible link at the cutoff switcch and a couple big
terminals in the 'under steering wheel'  compartment that can be rusty.

3  real common trouble spots

* Open controller fuse.  A 'fatigue failure.  Diirty fuse clip.

* open wire at controller fuse - often the wire is broken inside the
insulation at the push on terminal

* open coil on the sealing contact 'start and safety' relay.  The blue
'late issue' coils are real bad offenders here.  Replace with a 24 volt
DPDT ice cube relay.  Don't worry about a 36 to 24V dropping resistor on
the coil as these have a high coil resistance, don't heat up at all on
36.  This is a generic 'radio shack' industrial catalog part.   

Another couple not so common - stuck brake pedal motor cutout switch, or
wire fell off of seat safety switch.

Another trouble.  While working it quits.  Attempted restarts sometimes
starts but has no power.  Cause,  one of field wires has snagged on a
branch or somethiing and pulled loose.   These little wires underneath
should be well wire tied out of the way of possible snagging.  

Happy Etracin
Dave
Weymouth MA