C.E. Niehoff & Co. A2-344, A2-348, A2-350 Regulator Installation

A2-344, A2-348, & A2-350 14 V Regulators

with A9-4039 Temperature/Voltage Sense Harness

or A9-4050 Temperature/Voltage/IGN/D+

Sense Harness

Installation Instructions

These 14 V regulators can be used with or without A9-4039 or A9-4050 temperature/voltage sense harness

NOTICE

from the vehicle.

• When A9-4039 or A9-4050 temperature/voltage sense harness is not connected, regulator will operate in
fi xed voltage setting determined by the select switch position on the bottom of the regulator. See column 2
in Table 1.

• When A9-4039 or A9-4050 temperature/voltage sense harness is connected, regulator will automatically
optimize the charge voltage for battery type based on temperature. See column 3 in Table 1 and select
switch position based on battery type.

Table 1 – Regulator Select Switch Position

A9-4039/A9-4050 Harness

Switch Position

Not Connected (Voltage Select)

See NOTICE above

Position 1 13.8 V

Position 2 14.0 V
Position 3 14.3 V
Position 4 14.5 V

1. Before installing, turn regulator over a nd select appropri­ate switch position (See NOTICE above and Table 1 and
Figure 1).

2. Insta ll new regulator as described below:

• Mount A2-344 or A2-348 curved-base regulator on
alternator in the same position as the prev ious regula­ tor. Use screws and washers (if supplied). Torque regu­ lator mounting screws to 8.5 Nm/75 lb. in. See Figure 2.

• Mount A2-350 flat-base regulator in remote location
specified by customer. See Figure 3.

3. Plug alternator-to-regulator harness securely into 5-socket
receptacle on regulator.

4. See Figure 2 or 3:

• If not using A9-4039 or A9-4050 temperature/voltage
sense harness, keep cap on regulator.

• If using A9-4039 or A9-4050 temperature/voltage sense
harness:
a. Remove cap from regulator and plug harness
connector into 5-pin connector.
b. Harness length is 182 inches. Unused harness
length should be coiled up. Use cable ties every
12-14 inches to securely support harness between
regulator and battery. If harness lengt h must be
cut:

1) Black wire—Do not shorten unless absolutely
necessary. If necessary, cut off first 6 inches on
terminal end and save cut piece to reattach. Cut
length off of remaining black wire. Crimp and
solder two ends and seal with insulated butt
splice.

2) Red wire—cut to desired length and use termi­ nal to connect.

3) Attach terminal from black wire in harness to
battery negat ive post and terminal from red wire
to 14V battery positive post.
c. A9-4050 harness has two additional wire connections
for regulators requiring external ignition feed or D+
voltage sense/reference signal. See Fig ure 2.

1) Green wire (D+)—Connect splice to vehicle volt­ age sense/signal w ire. If terminal is used to run
relay, the relay coil must be diode protected and

A9-4039/A9-4050 Harness
Connected (Battery Type)

See NOTICE above

Maintenance (D Category)

Maintenance-Free (Group 31)

AGM

DO NOT USE POSITION #4

rated for proper volta ge. Crimp spliced end
securely. Use heat gun to seal splice. D+ ter­ minal provides 5 a mps of 14 V or 28 V
output.

2) Brown wire (IGN)—Connect splice to
switched voltage source from vehicle. Crimp
end securely. Use heat gun to seal splice.

5. If required, connect P terminal to tachometer or relay.
P terminal taps AC voltage, typically half the charge
voltage. Torque M6 terminal nut on regulator to 4.5 Nm/
40 lb. in.

6. W hen replacing an ex terna lly energized regulator with a
regulator listed in these instructions, existing energize
lead is no longer required. Insulate end of existing ener­gize lead, coil up, and support as needed.

P Terminal

Alternator-to-regulator connector

Figure 2 – A2-344/A2-348 Alternator-mounted Regulators

P Terminal

Alternator-to-regulator connector

Figure 3 – A2-350 Remote-mounted Regulator

Figure 1

LED

See step 4

LED

See step 4

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

Page 1 of 1

II180C