* Battery: This is the most common culprit. A weak or dead battery won't have enough power to even engage the starter motor, resulting in no click. Test the battery voltage with a multimeter. It should read around 12.6 volts when fully charged. A load test is even better, as it checks the battery's ability to deliver current under load.
* Battery Cables: Corroded or loose battery cables can prevent sufficient current flow to the starter. Inspect the cables at both the battery terminals and the starter motor connections for corrosion, looseness, or damage. Clean any corrosion with a wire brush and baking soda.
* Starter Motor: The starter itself could be faulty. It's possible the solenoid (the part that engages the starter motor) is bad, or the motor itself is worn out or seized. A mechanic can test the starter motor directly.
* Ignition Switch: While less likely, a failing ignition switch could prevent power from reaching the starter.
* Neutral Safety Switch (NSS): This switch prevents the car from starting unless the gear selector is in Park or Neutral. A faulty NSS will prevent the starter from engaging.
* Wiring: A break or short in the wiring between the battery, ignition switch, and starter motor could interrupt the circuit. This requires careful inspection of the wiring harness.
* Security System (if equipped): If your van has an aftermarket or factory alarm system, a problem with it could be preventing the starter from engaging.
Why the Camshaft Sensor Replacement Didn't Help:
The camshaft sensor is only involved in the engine's operation *after* the engine has started. It doesn't play a role in the starting process itself. Replacing it was likely a red herring, unless you had other starting-related symptoms prior to replacing the sensor.
Troubleshooting Steps:
1. Battery Test: This is the absolute first step.
2. Cable Inspection: Check for corrosion and tightness.
3. Listen Carefully: If you have a friend, have them turn the key while you listen closely to the starter area. A faint click might indicate a weak starter or a bad connection.
4. Jump Start (with caution): Attempt a jump start from a known good battery. If it starts, your battery is likely the issue.
5. Professional Diagnosis: If you're not comfortable working on your car's electrical system, take it to a mechanic for diagnosis.
Don't overlook the simplest things first (battery and cables). They are the most frequent culprits in no-start situations.
