The S-1A is a generator-set controller. It is used on generator sets from Northern Lights, including the NL843N and NL843N2.
| Symptom | Cause | Remedy |
|---|---|---|
| Battery Will Not Charge | Loose or corroded connections | Clean and tighten battery connections. |
| Below Normal Engine Temperature | Thermostat not working properly | Check thermostat. |
| Engine Emits Black or Gray Exhaust Smoke | Clogged or dirty air cleaner | Service air cleaner. |
| Engine Emits White Smoke | Improper fuel | Use correct fuel for temperature. |
| Engine Hard to Start or Will Not Start | Improper starting procedure | See starting section of this manual. Take special note of Bypass Switch operation. |
| Engine Knocks | Insufficient oil | Call your dealer. |
| Engine Overheats | Low coolant level | Fill tank or radiator to proper level; Check hoses for loose connections and leaks. |
| Engine Runs Irregularly or Stalls Frequently | Below normal engine temperature | Remove and check thermostat. |
| Entire Electrical System Does Not Function | Check DC circuit breaker | If breaker is tripped, reset it. |
| High Fuel Consumption | Improper type of fuel | Use correct fuel for temperature. |
| High Oil Consumption | Break-in period | Oil consumption decreases after break in. |
| Lack of Engine Power | Intake air restriction | Service air cleaner. |
| Low Oil Pressure | Low oil level | Fill crankcase to proper level. |
| Starter Cranks Slowly | Low battery output | Battery is too small; Battery cables are too small. |
| Starter Inoperative | Check DC circuit breaker | If the breaker is tripped, reset it. |
Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.