ENGINE RUNNING TOO COOL.

TM 10-3930-633-12

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. ENGINE RUNNING TOO COOL.

Step 1. Check operation of thermostat in restricting cold water flow through radiator.

Replace stuck thermostat.

Step 2. Check to determine if overcooking is the result of extended outside operation in low ambient temperatures.

Cover part of radiator core to obstruct air flow.

ELECTRICAL SYSTEM

1. BATTERY WEAK OR FAILS TO MAINTAIN CHARGE.

Step 1. Check battery electrolyte level.

Add distilled water to cover plates to inch, check for cracked case and replace battery

if cracks are found.

Step 2. Check for shorted cell in battery.

Replace battery.

Step 3. Check alternator belt tension and output.

Tighten alternator belt tension. Replace alternator if output is low and regulator

adjustment does not correct.

Step 4. Check voltage regulator adjustment (para 4-28).

Adjust regulator to specifications. Replace regulator if adjustment cannot be maintained.

Step 5. Check for excessive use of starter or dragging starter resulting in excessive battery drain.

Tune engine for easy starting or replace a dragging starter.

Step 6. Check for short to ground in electrical wiring.

Correct short condition.

2. STARTER CRANKS ENGINE SLOWLY.

Step 1. Check state of battery charge.

Refer to Item 1, "BATTERY WEAK."

Step 2. Check for loose or corroded battery cable terminals.

Clean and tighten battery cable terminals.

Step 3. Check for excessive amperage draw within starting motor.

Replace starter (para 4-29).

3. STARTER WILL NOT CRANK ENGINE.

Step 1. Check for loose, corroded, or broken cables to starting motor and solenoid switch.

Replace defective cables. Clean and tighten all cable terminals.

Step 2. Make certain that transmission shifter is in Neutral (N) position.

Place shifter in Neutral (N) position.

Step 3. Check make-and-break action of neutral start switch using ohmmeter.

Replace defective switch.

Step 4. Test starter for defects.

Replace defective starter.

Step 5. Check starter mounting; if loose, starter pinion may not engage flywheel.

Tighten starter mounting bolts.

IGNITION SYSTEM

1. ENGINE WILL NOT START.

Step 1. Check for spark at plugs; if no spark at plugs, check the following:

Step 2. Check ignition coil for shorts or grounds.

Replace ignition coil (para 4-40).

Step 3. Check distributor points adjustment and condition.

Adjust or replace points (para 4-34).

Step 4. Check capacitor for open circuit.

Replace capacitor.

Step 5. Examine rotor and distributor cap for cracks, burned areas, corrosion, and carbon tracking.

Replace defective rotor and distributor cap (para 4-34).

Step 6. Check for leakage in high-tension wires due to dampness.

Replace faulty wiring (para 4-32).

Step 7. Check spark plug gap setting.

Adjust gaps to specifications (para 4-31).

2. ENGINE RUNS ROUGH OR MISSES.

Step 1. Check ignition timing.

Adjust timing to specifications (para 4-38).

Step 2. Check to see that all high-tension wire terminals are tight at distributor and at plugs.

Tighten connections or replace faulty wiring.

Step 3. Check distributor advance mechanism (para 4-39).

Replace distribution if advance mechanism malfunctions.

Step 4. Check that high-tension wires are routed to proper plugs in firing order.

Disconnect wires and reinstall properly (para 4-32).

Step 5. Check for one or more defective spark plug.

Replace defective plugs (para 4-31).

4-7