DRESSTA TD-25M EXTRA, Service Manual

Page: 324 / 595

SECTION 8
ELECTRICAL
Page 48
TD-25M EXTRA DRESSTA
CRANKING MOTOR 42 MT
n. Solenoid Checks
A basic solenoid circuit is shown in Fig. 8.16. With all other leads disconnected, the solenoid
windings can be checked by making test connections as covered below. As shown in Fig. 8.17,
make connections to the S and ground return terminals. If needed, use the carbon pile to decrease
the battery voltage to the value specified in this Section and compare the ammeter reading with the
holding winding specifications
. A high reading indicates a shorted winding and a low reading
indicates excessive resistance. To check the pull-in winding connect from the solenoid switch
terminal to the solenoid motor terminal (Fig. 8.18). Compare with the
pull-in winding
specification.
A high reading indicates a shorted pull-in winding, and a low reading indicates
excessive resistance. To avoid excessive heating, leave the pull-in winding connected no more
than 10 seconds at a time. The current will decrease as the heating increases.
To check for grounds, move battery lead from M. terminal (Fig. 8.18) to a clean metal ground on
the solenoid case, (not shown). Ammeter should read zero. If not, hold-in or pull-in winding is
grounded.
NOTE: If needed to reduce the voltage to the specified value, connect the carbon pile between the
battery and the M terminal as shown. If the carbon pile is not needed, connect a jumper directly
from the battery to the M terminal.
Fig. 8.16. Solenoid Circuit with Ground Return Terminals
1. Hold - In Winding
2. Pull - In Winding 3. Start Switch
4. Battery 5. To Motor Windings