ARMY TM 9-6115-60412
NAVY NAVFAC P-8-633-12
Replace See figure 5-2.
Tag and disconnect wiring from MASTER switch S9R (24) terminals.
Remove locking nut and lockwasher from RCM front panel and remove MASTER SWITCH S9R
from the rear panel.
Install jumper wire across terminals 2 and 6 of replacement MASTER switch S9R.
Install MASTER switch S9R (24) from rear of RCM panel.
Secure switch at front RCM panel with lockwasher and locking nut.
Connect wires as tagged Remove and discard tags.
Close RCM panel and secure by locking three oval studs across the top of the panel.
HIGH COOLANT TEMP/LOW OIL PRESSURE/FAULT Lights (25, Figure 5-2). These lights Illuminate to
indicate that a fault condition has occurred at the main generator set.
Do not touch exposed electrical connection when a source of power such as
utility power or another generator set is connected to the load terminals. Death or
injury may result from failure to observe this warning.
Test Prior to performing individual tests on fault lamps and lamp holders, press the ANNUNCIATOR TEST
switch S1 5R with the RCM energized, to verify both the availability of 24 V dc control power and the
existence of an RCM fault indicator malfunction Horn LS1 R should sound and the HIGH COOLANT
TEMP, LOW OIL PRESSURE, and FAULT indicators (DS3R, DS2R, DS103R, respectively) should
light Perform the following tests on any fault lamp that falls to light when the ANNUNCIATOR test switch
S15R is pressed.
Open the RCM panel by unlocking three oval studs across the top of the panel.
Set multimeter to 50 V dc scale and check for 24 V dc at lamp holder (27) terminals of
malfunctioning indicator (25) at the same time that ANNUNCIATOR TEST switch S15R is being
pressed Press the ALARM SILENCE switch S16R to prevent horn LS1R from sounding when test is
If 24 V dc is not present at lamp holder (27) terminals, check blocking diodes D1 R through D6R
(depending on malfunctioning indicator) mounted on terminal block TB1R (11, Figure 5-1) Inside
RCM chassis. Test diodes as follows:
Release ANNUNCIATOR TEST switch S15R and test diode with multimeter set to RX1 scale.
Connect multimeter leads to diode terminals and then reverse multimeter connections to diode
Diode resistance reading should be infinite ohms going one way and zero ohms when multimeter
leads are reversed. Replace any diode that fails to meet this test. Tag and disconnect wiring to
diode by polarity for correct Installation of replacement component. If diodes are good, trace
wiring back to main generator set using FO-1. Trace back through main generator set circuits
until defective components are found Repair or replace as necessary.
(d) If 24 V dc is present at lamp holder (27) terminals, replace lamp (25) with a known good lamp. If
known good replacement lamp still does not light, replace the lamp holder (25).
Remove lens (26) covering lamp (25).
Tag and disconnect wiring from lamp holder (27).
Remove lamp holder (27) from panel by removing attaching hardware from rear.