C.E. Niehoff & Co. N1128-1 Alternator w/Link or w/Wiring Harness Installation - Manual (Page 2)

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C. E. Niehoff & Co. • 2021 Lee Street • Evanston, IL 60202 Tech Services Hotline 800-643-4633
For N1128-1 with serial numbers higher than 0059:
If B+ wire assembly needs to be replaced (see Figure 2):
Install new B+ wire assembly as described below:
1. Remove ADE cover plate and save hardware for reassembly.
2. Disconnect regulator harness wiring connections from diode modules. Leave field coil F– lead connection intact
and disconnect field coil F+ lead from diode module.
3. Remove and discard defective B+ wire assembly.
4. Connect new B+ wire assembly:
a. To B+ stud and torque screw to 28-29 Nm/21-22 lb. ft.
b. To diode modules and torque all screws to 4 Nm/35 lb. in.
5. Connect regulator harness to module screws and torque screws to 4 Nm/35 lb. in. Connect green ground wire to
heat sink and torque screw to 13.5 Nm/10 lb. ft.
6. Affix wire tie to field coil lead and one phase lead.
7. Using DMM (digital multimeter) set on diode test, connect red lead to B+ teminal on alternator and connect black
lead to B– terminal on alternator. Meter should read OL (blocking). Reverse leads, meter should read less than
0.8 V (flow). If meter reads zero in either direction, recheck wiring connections and diode orientation.
If diode module needs to be replaced (see Figure 2):
Replace diode module and install wire assembly as described below:
1. Follow steps 1-2 in "If B+ wire assembly needs to be replaced" above.
2. Remove and save B+ wire assembly.
3. Remove and save the hardware attaching the defective diode module and the ground link connected to it. Discard
the metal thermally conductive strip between the diode module and the black heat sink and replace with a new one.
Reinstall the ground link in the position shown in Figure 2 below. Torque diode module mounting screws to
12.5-13.6 Nm/ 9-10 lb. ft.
4. Continue with step 4 in "If B+ wire assembly needs to be replaced" above.
B+ wire assembly
➛
Ground link
Figure 2 – N1128-1 Alternator with B+ Wire Assembly
➛
➛
Black heat sink
Diode module
➛
Ground link
➛
➛
Black heat sink
Diode module
➛
➛
Metal
thermally
conductive
strip
➛
Ground link