Cummins 4BT – Intake Manifold Heater – Check

Check the battery voltage.
Minimum: 6.5 Volts.

Check the thermistor.
Disconnect the thermistor.
Turn the ignition switch to the “O N ” position.

NOTE: The ‘‘Wait to Start” light should come on.
The solenoids should click on.

Wait 20 seconds.
The solenoids should click off.
The “Wait to Start” light should begin flashing.
NOTE: The “Wait to Start” light will flash indicating an open circuit in the thermistor wiring. Disconnecting the thermistor simulates this condition.

Turn the ignition switch to the “ O FF” position.
Connect the thermistor wire harness.