TM-9-2320-273-34

TRUCK TRACTOR, LINE HAUL; LIGHT EQUIPMENT TRANSPORTER; TRUCK CHASSIS; MEDIUM EQUIPMENT TRANSPORTER

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

DECEMBER 1980

TM-9-2320-273-34 - Page 144 of 801

TM 9-2320-273-34

TA 074015

Figure 5-17. Positive Heatsink Test.

(6)

Connect the negative test lead to the positive heatsink and touch the positive lead to each of

the three diode terminals, one at a time (fig. 5-17). A low resistance should be indicated. (If a test light is

used, it should light.) If a high resistance is obtained, or if test light fails to light, an open diode is indi-

cated and the entire heatsink assembly must be replaced.

b. Negative Heatsink (Rectifier) Test.

NOTE

The negative heatsink is the one to which

the negative output terminal is connected.

The square hole in the terminal end of the

negative heatsink is smaller than the ter-

minal hole in the positive heatsink. If this

test is performed without removing the

heatsink from the end housing, verify that

steps (1) thru (4) in

a,

above have been

performed.

(1)

Connect the negative test lead to the negative heatsink and touch the positive test lead to

each of the three diode terminals, one at a time (fig. 5-18). If a low resistance reading is obtained, or if

test lamp lights, the diode is shorted and the entire heatsink must be replaced.

(2)

Connect the positive test lead to the negative heatsink and touch the positive lead to each

of the three diode terminals, one at a time (fig. 5-18). A low resistance reading should be obtained, and if

a test light is used, the lamp should light. If high resistance is indicated or the lamp does not light, it is

open and the entire heatsink assembly must be replaced.

5-16