C.E. Niehoff & Co. N1509/N1511/N2003 Troubleshooting Guides - Manual (Page 7)

Page 7
TG0014D
Section 3: Advanced Troubleshooting
N2003 LED
COLOR N2003 STATUS
TABLE 3 – N2003 Load & Battery Control Device Diagnostics
Alternator not charging. Unlit (Clear)
Solid Amber
Solid Red
Alternator RPM below 1500 rpm.
Batteries are disconnected from system and
battery voltage is less than 24.5 V. Alternator
28 V B+ output terminal is at regulated voltage.
Pin Function
TABLE 4 – N2003 Harness Plug
Pin Functions
A
B
C
D
E
Battery Ground
Chg. System Indicator Ground Signal
Battery Disconnect Ground Signal
AC In from Regulator AC Terminal
Battery Voltage Sense/Trickle Charge
Figure 5 – N2003 Load & Battery Control Device
Figure 4 – N2003
Control Harness Receptacle
N2003 Load & Battery Control Device
DESCRIPTION AND OPERATION
Main diagnostic feature of the LBCD is an LED
display located on the side of the device. The LBCD
monitors alternator output and vehicle electrical
system and regulated voltage. If system voltage falls
below 20.5 volts, N2003 will disconnect batteries
and supply trickle charge. See Table 3 for diagnostic
features and LED display explanations.
Solid Green System operating properly. Batteries are
connected to system. Alternator charging.
LED
12 V Battery
T
24 V Load
T
12 V Load
T
24 V Battery
T
T
CHARGING
SYSTEM LED
STATUS
ON
ON
OFF
OFF