MULTIQUIP DCA Series - Engine Starter (Crank) Relay

PAGE 64 — GENERATOR SERVICE AND TROUBLESHOOTING MANUAL — REV. #0 (08/29/23)
ENGINE STARTER
(
CRANK
)
RELAY
ENGINE START (CRANK) RELAY
For use on DCA20, 25 36, 45, 70 (Isuzu) and 125
generators. See next page for other model genrators.
As shown in Figure 71, a typical starter solenoid has one
small terminal for the starter control wire and two large
terminals for the positive battery cable and the thick wire
that provides power to the starter motor. The B+ battery
terminal connects the solenoid directly to the positive
battery cable.
The B+ battery voltage is also connected to the normally
open contact on the starter relay (pin 2). When the starter
relay is energized at pin 3 (coil) by the ECU crank signal
output (pin 6), this will cause the normally open contact to
close and the voltage is sent via pin 1 of the starter relay
to the starter solenoid (crank signal “S”).
Pin 4 on the starter relay is provided a ground signal via
the starter cut relay (pins 3 and 6). The starter cut relay
is controlled by the engine control module (ECM). Pin 1
on the starter cut relay is connected to B+ via the ECM
controller while pin 2 is provided a ground signal via the
ECM controller.
Once the engine has started, the engine ECM will send
a ground signal to pin 2 of the starter cut relay, which will
cause the starter crank relay to be de-energized (the ground
signal is removed from pin 4 on the starter crank relay),
thus ending the cranking cycle.
Figure 70. 4-Pin Starter (Crank) Relay
COIL
3
4
1
2
ANODE
CATHODE
3
4
CN17
ECU 750/754/845
CONTROLLERS
PIN 6
OUTPUT
SIGNAL
WHT.
1
2
5
3
6
NC
NO
COIL
CN15
s
B+
STARTER CUT
RELAY
POS.
NEG.
BLK.
RED
BATTERY
STARTER
CN16
TO CHASSIS
GND
CN14
STARTER (CRANK)
RELAY (4-PIN)
TO CN2 B+
CONTROLLER
TO CN1 V14
CONTROLLER
4-PIN
YEL
WHT
BRN
BRN
BRN
RED
WHT
GRN
GND.
STARTER (CRANK)
RELAY
COIL
3
4
1
2
NO
5-PIN
1
2
5
3
6
NC
COIL
STARTER CUT
RELAY (5-PIN)
CN6
STARTER
SOLENOID
BASLER/DIEF
CONTROLLERS