C.E. Niehoff & Co. 200, 300 User Manual

Series 200 & 300 Alternators

Voltage Regulator Upgrade

Installation Instructions

This symbol is used to indicate special instructions

NOTICE

on installation, operation or maintenance that are
important but not related to personal injury hazards.

300 Series – A1-300, A1-301, A1-302, A1-303, A1-305,
A1-306, A1-307

N1101, N1102, N1103, N1108, N1111, N1112, N1114, N1115,
N1117, N1118, N1119, N1120, N1121, N1122, N3017, N3018,

N3037, N3038

1. No modification to cover assembly is needed.

2. New voltage regulator circuit board fits in place of old
one as shown in Figure 1.

3. Wire as shown in Figure 2.

A1-305 and N1114 may have an additional brown lead

(see Figure 1) not required for new regulator. Trim lead
and tape exposed end to insulate from contact with other
components.

Voltage Select Switch Position

A2-431 Reg. A2-432 Reg. A2-433 Reg.
Position 1—13.8 V Position 1—27.6 V Position 1—27.6 V
Position 2—14.2 V Position 2—28.0 V Position 2—28.5 V
Position 3—14.6 V Position 3—28.5 V Position 3—37.2 V
Position 4—14.6 V Position 4—29.0 V Position 4—38.3 V

 Brown Lead not needed

for new regulator





Figure 1 - Series 300 Circuit Board

Field Lead

(white wire with ring terminal)

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



“B-” Lead

(heavy black wire)

Figure 2 - Series 300 Wiring

Field lead white wire with fl ag

NOTICE

terminal must be attached to heat
sink stand-off. There is no terminal on new board for

fi eld lead with fl ag terminal.

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200 Series – A1-200, A1-201, A1-202
N1025, N1026, N1031, N1036, N1037, N1077, N1079,

N1080, N1085, N3036, N7024, N7031, N7040

1. Remove end housing assembly, voltage adjust-

ment cover, screw, and voltage adjustor insula­tor.

2. Using the third hole as the pilot hole, drill a

9/16” hole.

3. Deburr new hole to prevent damaging new

switch on new circuit board.

4. Install new circuit board and wire per

Figure 4.

Voltage Select Switch Position
A2-434 Reg. A2-435 Reg.
Position 1—13.8 V Position 1—27.6 V
Position 2—14.2 V Position 2—28.0 V
Position 3—14.6 V Position 3—28.5 V
Position 4—14.6 V Position 4—29.0 V

Figure 3 - Series 200 Cover Assembly

“R” Lead

(brown wire)

“Y” Lead

(brown wire)





Field Lead

(white wire)

Output Lead

(red wire)







GROUND

(white wire)

Figure 4 - Series 200 Wiring

C. E. Niehoff & Co. • 2021 Lee Street • Evanston, IL 60202 Tech Services Hotline [phone]

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