Controller (Fig. 11)
The controller senses the condition of various switches,
such as the transport switch and aerate start switch and
directs power output to allow certain machine functions,
such as aerate engage, disengage and timing of those
functions.
Because of the solid state circuitry built into the control-
ler, there is no method to test it directly. The controller
may be damaged if an attempt is made to test it with an
electrical test device, such as a volt-ohm meter.
IMPORTANT: Before welding on the machine, dis-
connect both battery cables from the battery, dis-
connect both wire harness plugs from the electronic
control unit and disconnect the terminal connector
from the alternator to prevent damage to the electri-
cal system.
Lights (LED’s) on the controller indicate the condition of
the interlock switches. The LED’s, in conjunction with
the following tests for interlock switches, should be used
to help isolate a problem in an interlock switch, wiring or
the controller (see Wiring Schematics and Diagrams).
2
1
Figure 11
1. Red light
2. Yellow light
3. Green light
Neutral Switch and Transport Switch (Fig. 12)
The neutral switch is normally open (N.O.) and is closed
when traction bail is neutral. The transport switch is
normally closed (N.C.) and is open when the traction bail
is in neutral.
IMPORTANT: The neutral and transport switches
have three (3) terminals. The NEUTRAL SWITCH
must have the wires connected to the “COMMON”
and “N.O.” terminals. The TRANSPORT SWITCH
must have the wires connected to the “COMMON”
and “N.C.” terminals. If the wires are not connected
to the correct terminals, on each switch the safety
interlock circuit will not function properly.
Test the switch by disconnecting the wires from the
switch terminals and connecting a continuity tester
across the two terminals that had wires connected to
them. With the engine turned off, slowly push the trac-
tion bail in a forward and reverse direction while watch-
ing the continuity tester. There should be indications that
the switch is opening and closing. Allow the traction bail
to return to neutral. There should be continuity across
the terminals of the neutral switch and no continuity
across the terminals of the transport switch. (See Neu-
tral Switch and Transport Switch Replacement and Ad-
justment in the Repairs section of this chapter for
replacement and adjustment procedures.)
1
3
2
Figure 12
1. Neutral switch –– N.O. (black & red/blue wires)
2. Transport switch –– N.C. (yellow & gray wires)
3. Switch tab
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