TEST OR INSPECTION
Water tank heaters turn ON when water in water tank is below 40ºF (4.4ºC), and turn OFF
when water in water tank reaches 60ºF (15.6ºC). Ensure water in water tank is below
40ºF (4.4ºC), when performing Step 26.
Check front water tank heater and rear water tank heater for proper operations, when
water in water tank is below 40ºF (4.4ºC). Rear water tank heater shown.
If front water tank heater does not heat up, go to Step 28.
Turn hydraulic generator OFF (WP 0021). Turn vehicle engine OFF
(TM 9-2320-347-10). Turn battery disconnect switch to OFF position (WP 0007). Open
water tank heater control box (WP 0301). Remove rear water tank heater guard and
water tank heater cover (WP 0300). Cut red wire at butt splice in rear water tank heater.
Check for continuity across red wire from rear water tank heater relay terminal, to rear
water tank heater thermostat butt splice.
If there is continuity, replace rear water tank heater (WP 0300).
If there is no continuity, replace rear water tank power cord (WP 0361).