C.E. Niehoff & Co. N1225/N1387 Alternator Installation - Manual

II225A
Page 1 of 2
N1225 or N1387 Alternator
with N3135 or N3225 Regulator
Installation Instructions
OEM Wiring Connections - Dual or Single Voltage
Vehicle harness
(to +14V battery)


Regulator –
“+14V”
terminal

Regulator
Boot (p/n N9564,
supplied in
envelope assembly)

Nut, 5/16-18 UNC-2B;
torque to 5.6 Nm / 50 lb.in.
Washer


Nut, 1/4-20; torque to
2.8 Nm / 25 lb.in.
Washer
Regulator – “IGN” Terminal
Boots (p/n N9464,
supplied in
envelope assembly)
Vehicle harness 
Regulator – “AC” Terminal

Locknut, #10-24;
torque to 2.3 Nm / 20 lb.in.






DUAL VOLTAGE (28 V/14 V) applications
(see other side for single voltage):
1. Connect as shown on this page in
Figures 1a-c.
Figure 1a – Regulator Dual Voltage Wiring Connections
Washer
Regulator
receptacle

Phase
connector cap

Alternator

Terminal on
Vehicle “B+” lead
Lock Washer
Washer 
.3750-16 UNC-2B;
torque to
15 Nm / 11 lb.ft.

Figure 1b – Positive Terminal Connections

+28 V B+ Bolt
on alternator


Washer
Lock Washer
.3125-18 UNC-2A;
torque to 9 Nm / 80 lb.in. 

Ground Bolt
on alternator
Terminal on
vehicle ground lead

Figure 1c – Ground Terminal Connections

