TM 9-6115-729-24
0013
ELECTRONIC TECHNICIAN (ET) TROUBLESHOOTING - Continued
CORRECTIVE ACTION - Continued
e. Observe the voltmeter.
(1) If the voltmeter does not measure 24 +/- 3.0 Vdc, ensure that the circuit
breaker is not tripped.
(2) Check the harness from the battery to the air inlet heater relay. Make
any necessary repairs (WP 0090).
(3) Retest and ensure the voltmeter measures 24 +/- 3.0 Vdc.
f.
On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
STEP 10.
Check for voltage output at the air inlet heater relay.
a. Reconnect the wire from the +battery to the air inlet heater relay.
b. Remove the wire to the air inlet heater from the air inlet heater relay.
c.
Connect a voltmeter between the output terminal of the air inlet heater relay
and engine ground.
d. Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
e. Observe the voltmeter. The voltmeter should not measure any voltage, since
the air inlet heater relay is not energized. If the voltmeter measures 24 +/- 3.0
Vdc, ensure that the voltmeter is connected to the output side of the air inlet
heater relay.
f.
Run the Air Inlet Heater Override on the Cat ET and observe the voltmeter.
g. On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
NOTE
The Air Inlet Heater Override has a one minute timer in order to disable the test when the time
expires.
h. If the voltmeter does not measure 24 +/- 3.0 Vdc, proceed to STEP 11.
STEP 11.
If the problem is not resolved, check the wiring between the air inlet heater relay
and the air inlet heater.
a. Reconnect the wire from the air inlet heater relay to the air inlet heater.
b. Disconnect the wire between the air inlet heater relay and the air inlet heater
from the air inlet heater.
c.
Connect the voltmeter between the wire at the air inlet heater and engine
ground.
d. Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
0013-9
