4-4. INTRODUCTION - Continued
i. Electrical System.
(1) Check engine, starter motor, and instrumentation wiring for proper connections and condition of
wiring insulation. Pay particular attention to the wiring harnesses as they pass through bulkheads or
holes in the frame. Ensure all grommets are in place.
(2) Check battery compartment and battery connection. Clean away any corrosion, neutralizing the acid
with baking soda solution. Paint any bare or rusty steel. Coat all battery connections with a
petroleum jelly. Check tightness of battery connections.
j. Auxiliary Power Unit.
(1) Inspect auxiliary power unit, removing any seals plugs or tape used to seal air inlets or ports during
(2) Check crankcase oil level and inspect oil on dipstick for cleanliness.
Take an oil sample for
analysis. Top up, or drain and refill crankcase as required.
(3) Examine air cleaner element for dirty or restricted condition. Replace as required.
(4) Inspect engine and all piping connections for evidence of leakage. Repair asrequired.
(5) Inspect fuel line connections for evidence of leakage. Tighten, or remake joints as required.
k. Main Engine Test.
(1) Start main engine.
(2) When engine is running, check:
- oil pressure builds up to at least 20 psi (140 kPa); warning lamp
- air pressure warning lamps extinguish. (primary and secondary)
- engine air filter gauge remains in safety zone
- engine water temperature warning lamp extinguishes
- battery voltage and current (amps) remain in safety zone
- transmission oil temperature lamp extinguishes
(3) Check operation of all lamps and beacons:
- tail, park and head lights (high beam and low beam)
- marker lights
- panel lights
- dome lights
- rear beacon lights
- compartment lights
- hose pick-up lights
- engine compartment lights
- dash lights
(4) Check operation of rear buzzer, main siren, and PA system.