Why generators show "engine will not crank": 179 documented causes and brand-specific fixes, compiled across 16 manufacturers.
Weak battery
4 brands- Doosan: Replace battery.
- Ingersoll Rand: Replace battery.
- John Deere: Replace battery.
- Katolight: Replace battery.
Corroded or loose battery connections
4 brands- Doosan: Clean battery terminals and connections.
- Ingersoll Rand: Clean battery terminals and connections.
- John Deere: Clean battery terminals and connections.
- Katolight: Clean battery terminals and connections.
Defective main switch or start safety switch
4 brands- Doosan: Repair switch as required.
- Ingersoll Rand: Repair switch as required.
- John Deere: Repair switch as required.
- Katolight: Repair switch as required.
Starter solenoid defective
4 brands- Doosan: Replace solenoid.
- Ingersoll Rand: Replace solenoid.
- John Deere: Replace solenoid.
- Katolight: Replace solenoid.
Starter defective
4 brands- Doosan: Replace starter.
- Ingersoll Rand: Replace starter.
- John Deere: Replace starter.
- Katolight: Replace starter.
Possible fault with control or starting system
3 brands- Cummins/Onan: Check for the following conditions: Fault lamp on. Correct fault and reset control; Poor battery cable connections. Clean the battery cable terminals and tighten all connections; Discharged or defective battery. Recharge or replace the battery; Contact an Onan Dealer or Distributor for assistance if none of the above.; Check for the following conditions: fault lamp on — correct fault and reset control; poor battery cable connections — clean the battery cable terminals and tighten all connections; discharged or defective battery — recharge or replace the battery; contact an Onan Dealer or Distributor for assistance if none of the above
- Detector: Check for the following conditions: fault lamp on — correct fault and reset control; poor battery cable connections — clean the battery cable terminals and tighten all connections; discharged or defective battery — recharge or replace the battery; emergency stop button (if equipped) pushed in — to reset, pull switch out and move Run/Stop/Remote switch to Stop position, then push test switch to Reset/Lamp position; contact an authorized service center if none of the above.
- Ford: Check for the following conditions: fault lamp on — correct fault and reset control; poor battery cable connections — clean the battery cable terminals and tighten all connections; discharged or defective battery — recharge or replace the battery; emergency stop button (if equipped) pushed in — to reset, pull switch out and move Run/Stop/Remote switch to Stop position, then push test switch to Reset/Lamp position; contact an authorized service center if none of the above.
Faulty starter solenoid
3 brands- Generac: Replace solenoid.
- Isuzu: Replace solenoid.
Blown fuse
2 brands- Generac: Correct short circuit condition by replacing 7.5 A fuse in generator control panel. Contact an IASD if fuse continues to blow.; Correct short circuit condition by replacing 7.5 A fuse in generator control panel. Contact an Independent Authorized Service Dealer (IASD) if fuse continues to blow.
- Isuzu: Replace fuse.
Indicates possible fault with control or starting system
2 brands- Cummins/Onan: Check for the following conditions: Fault lamp on. Correct fault and reset control; Poor battery cable connections. Clean the battery cable terminals and tighten all connections; Discharged or defective battery. Recharge or replace the battery; Contact a Cummins Dealer or Distributor for assistance if none of the above.; Check for the following conditions: Fault lamp on. Correct fault and reset control; Poor battery cable connections. Clean the battery cable terminals and tighten all connections; Discharged or defective battery. Recharge or replace the battery; Contact an Onan Dealer or Distributor for assistance if none of the above.
- Ford: Check for the following conditions: fault lamp on — correct fault and reset control; poor battery cable connections — clean the battery cable terminals and tighten all connections; discharged or defective battery — recharge or replace the battery; contact an authorized service center for assistance if none of the above
Faulty starter motor
2 brandsLow battery output voltage or discharged battery
2 brands- Generac: Charge or replace batteries. See Battery Installation and Replacement.
- Isuzu: Charge or replace batteries. See Battery Inspection.
Loose or corroded connections
2 brands- Generac: Clean and tighten connections. Replace as necessary.
- Isuzu: Clean and tighten connections.
Faulty start circuit relay
2 brands- Generac: Contact a GMP ASD.
- Isuzu: Contact a GMASD.
Faulty main switch or start safety switch
2 brands- Generac: Repair switch as required.
- Isuzu: Repair switch as required.
Faulty starter
2 brands- Generac: Replace starter.
- Isuzu: Replace starter.