Thermo King SB-III 30 SR+, Manual

Page: 57 / 120

Engine Maintenance (Rev. 04/02)
47
a. If the pull-in coil does not energize, check the
resistance of the pull-in coil by placing an ohmme-
ter between the white wire (8DP—pin B) and the
black wire (CH—pin C) in the fuel solenoid con-
nector. The resistance of the pull-in coil should be
0.2 to 0.3 ohms. If the resistance of the pull-in coil
is not in this range, replace the fuel solenoid.
NOTE: If the pull-in coil fails, make sure to
replace the fuel solenoid relay with a Pot-
ter-Brumfield relay P/N 44-9111. This particular
relay is needed for the high current flow through
the hold-in coil.
b. If the pull-in coil does energize, go to step 8.
8. Test the hold-in coil.
a. Energize the hold-in coil by placing a jumper
between the red wire (8D—pin A) in the fuel sole-
noid connector and the positive battery terminal.
b. Momentarily energize the pull-in coil by placing a
jumper between the white wire (8DP—pin B) in
the fuel solenoid connector and the positive battery
terminal. The fuel solenoid should make a definite
click when the pull-in coil is energized, but should
not click when the pull-in coil is de-energized.
c. De-energize the hold-in coil by removing the
jumper from the red wire (8D—pin A) and the pos-
itive battery terminal. The fuel solenoid should
make a definite click when the hold-in coil is
de-energized.
d. If the hold-in coil does not function properly,
check the resistance of the hold-in coil by placing
an ohmmeter between the red wire (8D—pin A)
and the black wire (CH—pin C) in the fuel sole-
noid connector. The resistance of the hold-in coil
should be 24 to 29 ohms. If the resistance of the
hold-in coil is not in this range, replace the fuel
solenoid.
e. If the hold-in coil does function properly, go to
step 9.
9. Reconnect the fuel solenoid connector and the main
wire harness connector.
10. Remove the fuel solenoid relay from its socket and
make sure the On-Off switch is in the ON position and
the unit is in the Relay Board Test Mode [RUNR].
11. Check the voltage on the 8D circuit at the 85 terminal
in the fuel solenoid relay socket. Refer to the following
illustration to identify the terminals in the relay socket.
a. If battery voltage is not present on the 8D circuit,
check the 8D circuit and the related circuits and
components for a fault (minimum voltage is 10
volts).
b. If battery voltage is present on the 8D circuit, go to
step 12.
12. Check the voltage on the 2A/2B circuit at the 30 termi-
nal in the fuel solenoid relay socket.
a. If voltage is not present on the 2A/2B circuit,
check the 2A circuit for an open or a short.
b. If battery voltage is present on the 2A/2B circuit,
go to step 13.
1. 30 Terminal—2A/2B Circuit
2. 85 Terminal—8D Wire
3. 87 Terminal—8DP Wire
4. 86 Terminal to Timer
Relay Socket Terminal Identification