TM 9-4910-663-34
(3)
Remove the panel retaining hardware from the sides and front I of the control panel, raise the control
panel, and secure it in the up position with the lock bolt.
(4)
Unsnap the wires from the relay terminals.
(5)
Unsolder the other wires from the relay terminals.
(6)
Remove the screw that attaches the relay to the resistor and shunts panel and remove the relay.
(7)
Reverse the procedures of steps (1) through (6) to install the replacement relay.
3-13.
DIODE ASSEMBLY (fig 2-10)
a.
Description. The diode assembly contains the bridge rectifiers for the DC variable volts, battery charge, and
relay control circuits.
b.
Testing. Test each of the three bridge rectifiers on the diode assembly as follows:
(1)
Remove lower rear panel.
(2)
Connect the positive lead of an ohmmeter to the positive output terminal of the bridge rectifier, and
connect the negative lead of the ohmmeter to each AC input terminal of the bridge rectifier in turn. The ohmmeter
should indicate a high resistance. Then, repeat the resistance measurements with the ohmmeter leads reversed. The
ohmeter should indicate zero ohm or a very low resistance. If the correct indications are not obtained, replace the
rectifier.
(3)
Connect the negative lead of the ohmmeter to the negative output terminal of the bridge rectifier, and
connect the positive lead of the ohmmeter to each AC input terminal in turn. The ohmmeter should indicate a very high
resistance. Then, repeat the resistance measurements with the ohmmeter leads reversed. The ohmmeter should
indicate zero ohm or a very low resistance. If the correct indications are not obtained, replace the rectifier.
(4)
Repeat steps (2) and (3) for each of the other two rectifiers on the diode assembly.
c.
Repair Instructions. Instructions for removal of the diode assembly from the test stand are provided in para 2-13.
(1)
Remove the retaining hardware from the rectifier that is to be replaced.
(2)
Remove the defective rectifier.
(3)
Install the replacement rectifier.
Change 1 3-27
