TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
20. STOPLIGHT INOPERATIVE
Test stoplight switch voltage.
Step 1. Place battery switch to OFF position.
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.
Step 2.
Disconnect both leads 75 at stoplight switch.
Step 3.
Place battery switch to ON position and light switch to STOPLIGHT position.
NOTE
For stoplight lead test, brake pedal must be depressed and air
pressure maintained.
Step 4.
Set multimeter to 50-volt range.
Step 5.
Connect multimeter negative lead to good ground and positive lead to each exposed lead
75 and note voltage indicated.
a. Meter should indicate battery voltage through one of the leads 75. If no voltage is
present, perform malfunction 16, test 4. If voltage is indicated, connect that wire to
one terminal of stoplight switch.
b. With brake pedal depressed, connect multimeter positive lead to exposed stoplight
switch terminal. Multimeter should indicate battery voltage.
c. If battery voltage is indicated, stoplight switch is operational. If no voltage is
indicated, replace stoplight switch (para. 3-111).
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