TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
HEATER SYSTEM
37. HEATER WILL NOT OPERATE WITH SWITCH IN LOW POSITION (HIGH POSITION OPERATION NORMAL)
Test 1. Test lead 569A for voltage.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect lead 569A from heater switch.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead
569A. Multimeter should indicate 12 to 13-volts.
a. If battery voltage is not indicated, go to test 2.
b. If battery voltage is indicated, replace defective heater switch (para. 3-107).
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