Engine Cranks Slowly

Perform the following checks:

• Battery - Battery Inspection/Test. Refer to Battery Inspection/Test (Non-HP2) .
• Wiring - Inspect the wiring for damage. Inspect all connections to the starter motor, solenoid, battery, and all ground connections. Refer to Circuit Testing , Wiring Repairs , Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
• Engine - Make sure the engine is not seized. Refer to Symptoms - Engine Mechanical or Symptoms - Engine Mechanical in Engine Mechanical.

If the battery, the wiring and the engine are functioning properly and the engine continues to crank slowly, replace the starter motor. Refer to Starter Motor Replacement (4.8L, 5.3L, and 6.0L Engines)  or Starter Motor Replacement (8.1L Engine) .