TM 9-4910-663-34
3-12.
RESISTOR AND SHUNTS PANEL ASSEMBLY (fig 2-10)
a. Description. The resistor and shunts panel assembly provides mounting facilities and electrical connections for
resistors used in the fixed resistance regulator check circuit, and shunts and a shunt switching relay used with instrument
panel DC ammeters. Repair at the direct support maintenance level is limited to inspection and test to locate a defective
part, and removal and replacement of that part.
b. Inspection of Shunts R19, R28, R29, R30, and R31 (fig 3-2).
(1)
Disconnect main power from the test stand.
(2)
Remove the panel retaining hardware from the upper and lower rear panels of the test stand, and remove
the upper and lower rear panels.
(3)
Remove the panel retaining hardware from the sides and front of the control panel, raise the control panel,
and secure it in the up position with the lock bolt.
(4)
Inspect the shunts for indications of burning and melted solder.
c. Testing Resistors R10, R11, R12, and R13 (fig 3-2).
(1)
Disconnect main power from the test stand.
(2)
Remove the panel retaining hardware from the upper and lower rear panels of the test stand, and remove
the upper and lower rear panels.
(3)
Using an ohmmeter, measure the resistance across each resistor. The resistances should be 1/4 ohm ±5%
for resistor R10, 1-1/2 ohms ±10% for resistor R11, 2-1/4 ohms ±10% for resistor R12, and 7 ohms ±10% for resistor
R13.
d. Testing Relay K9 (fig 3-2).
(1)
Disconnect main power from the test stand.
(2)
Remove the panel retaining hardware from the sides and front of the control panel, raise the control panel,
and secure it in the up position with the lock bolt.
(3)
Inspect the contacts of relay K9 for excessive pitting.
(4)
Disconnect the wire lead from one relay coil terminal. Using an ohmmeter, measure the resistance across
the coil terminals. The resistance should be 400 ohms ±10%.
e. Removal and Replacement of Shunt R19, R28, R29, R30, or R31.
Change 1 3-24
