Alternator Voltage Regulator - TM-10-3930-621-120124

must be the same.

(5) When using a booster battery, connect posi-

tive terminal of booster battery to positive terminal

of truck battery and negative terminal to negative

terminal.

(6) When connecting a battery charger to bat-

tery, connect the same as for booster battery.

e. Operation. Start truck and check alternator oper-

ation. Alternator should show charging rate on am-

meter.

3-42. Alternator Voltage Regulator

a. General. The voltage regulator is the transistor

or solid state type. The regulator limits the voltage

developed by the alternator and protects the circuits

from too high a voltage. Protection is also provided

to keep from over charging the battery.

b. Removal. Refer to figure 3-27 and remove the

voltage regulator as follows:

(1) Disconnect three wires from regulator term-

inals. Tag wires for correct installation.

(2) Remove three screws, nuts, and lock washers

and remove regulator from battery box.

Figure 3-26. Alternator, installed view

c. Installation. Refer to figure 3-26 and install the

alternator as follows:

(1) Install alternator on mounting bracket and

secure with two screws and nuts and four lock wash-

ers. Do not fully tighten screws.

(2) Move alternator towards engine and install

drive belt over alternator pulley. Secure top of alter-

nator to adjusting strap with screw. lock washer and

flat washer. Do not fully tighten screw.

(13) Refer to paragraph 3-12 and adjust fan belt

tension. Tighten mounting and adjusting brace

screws securely.

(4) Connect wires to battery and ground term-

inals on alternator.

(5) Install plug to connect alternator R and F

terminals to circuit.

(6) Connect battery ground cable to battery

(para 3-11).

d. Preparation for Operation. The following points

must be adhered to before returning the truck to

operation.

(1) Do not polarize alternator.

(2) Do not short or ground across any of the

terminals of the alternator or regulator.

(3) Never operate the alternator on an open cir-

cuit. Check all connections in the circuit for security.

Figure 3-.27. Voltage regulator, installed view.

(4) Ground polarity of alternator and regulator

3-28