Voltage Regulator - TM-10-3930-632-120057

TM 10-3930-632-12

(c) If the voltage reading still exceeds

0.3 volts, check the alternator for shorted or grounded

fields. Remove lead from alternator field terminal and

connect an ammeter in series with the field winding.

b. Alternator Removal

(1)

Tag the electrical leads to the

alternator terminals. Disconnect the leads.

CAUTION

Always disconnect the battery cable from

the positive battery terminal before making

electrical repairs to the truck.

(2) Loosen the fan and alternator belts and

remove the alternator as shown in figure 4-39.

c. Installation

CAUTION

Improper location of the lower mounting bolt

Figure 4-14. Checking Field Relay

spacers will cause pulley misalinement and

premature belt wear.

Install the alternator in reverse order of removal.

(3)

To check for excessive circuit

Spacers on the lower mounting bolt are placed between

resistance, connect a voltmeter from the positive battery

the alternator and the rear mounting bracket. These

post to the field terminal of the alternator. Turn on

spacers provide for proper alternator to water pump

ignition switch but do not start engine. Check voltmeter

pulley alinement.

readings as follows:

(a) If reading exceeds 0.3 volts,

4-32. Voltage Regulator

excessive line resistance is indicated. Clean and tighten

a. Testing and Adjustment. Figure 4-15

all connections at and between battery insulated post

illustrates the voltage regulator with the cover removed

and regulator "V" terminal, and at regulator "F" terminal

to identify the internal parts of the regulator.

and alternator field terminal.

(b) If voltage reading still exceeds 0.3

volts, clean the alternator "Bat" terminal, field relay

contacts and voltage regulator contacts.

Change 1 4-30