C.E. Niehoff & Co. N1388: N7153 Control Unit Assembly/ N7155 B+ Output Stud Replacement Instructions - Manual

II0114B
Page 1 of 2
N1388 Alternator
N7153 Control Unit Assembly
and/or N7155 B+ Terminal
Replacement Instructions
1. Remove hardware and cover plates from:
a. top of control unit
b. front of control unit
c. drive end housing
2. Remove and save voltage adjust plug from control
unit assembly (this step is not necessary when
replacing B+ terminal).
3. Carefully remove potting in front of terminal strip
in control unit to expose six terminals.
4. Disconnect two field coil wires, B+ wire, ground
wire, two stator Y-taps, and phase (AC) wire from
terminal strip.
5. Remove and save the hardware attaching the control
unit
assembly.
6. Carefully dig out all of the potting inside the control
unit cavity. DO NOT DESTROY ANY INTERNAL
WIRING.
7. Remove control unit assembly from cavity.
8. Clean out any loose debris in exposed cavity hole
and from wire terminals that will be reattached to
the control unit assembly.
9. Replacing control unit assembly ONLY—proceed
to step 19 on page 2.
Replacing B+ terminal—proceed to step 10 at
right.
Figure 1 – Replacing Control Unit Assembly and/or
B+ Terminal on N1388 Alternator
Follow steps 10-18 below to complete B+ terminal
replacement:
10. Remove and save hardware and stud on external B+
terminal.
11. From internal B+ stack, disconnect hardware,
B+ wire, and two rectifier wires.
12. Remove and save hardware attaching the defective
B+ terminal to the housing.
13. Remove defective B+ terminal.
14. Apply bead of Dow Corning® SE9186L RTV
coating or equivalent on mating surfaces between
new B+ terminal plate and drive end housing.
15. Install new B+ terminal in cavity. Use a suitable
adhesive such as Loctite® 222 on three mounting
screws. Torque mounting screws to 4.8 Nm/40 lb. in.
16. Using sandpaper and a cloth, remove all potting
debris from both rectifier wire terminals and B+
wire terminal to ensure the mating faces make
clean contact with each other.
17. Reconnect wiring removed from internal B+ stack in
step 11 according to the stacking order shown in
Figure 2. Torque to 28.2-29.3 Nm/20.3-21.6 lb. ft.
18. Proceed to step 19 on page 2 to complete assembly.
V
Control unit assembly
V
B+ wire
V
Phase
(AC) wire
V
Ground wire
V
Two fi eld coil wires
V
B+
wire
Two
rectifi er
wires
B+
terminal
Flat
washer
Disc
spring
washer
Bolt
Figure 2 – Internal B+ Stacking Order
voltage
adjust
plug
V V
V
Two stator
Y-taps
V