Generac — Testing the Fuel Lockoff Solenoid
Testing & diagnosis · Gaseous fuel lockoff solenoid
From a Generac service manual covering: GN-190, GN-220, NP-30G, NP-40G. Check it applies to your exact model before use.
Applies to: Generac NP-30G, Generac GN-190 / GN-220 engine, Generac GN-220 engine
Procedure
- Set a VOM to read battery voltage (12 VDC).
- Connect the VOM test leads across Wire 14 (Red) at the solenoid and a clean frame ground.
- Set the fuel primer switch on the generator panel to its ON position.
- The meter should indicate battery voltage and the solenoid should energize open.
- If battery voltage is indicated but the solenoid does not energize, replace the lockoff solenoid.
- If battery voltage is not indicated, a problem exists in the DC control system.
Tools required
- VOM (volt-ohm-milliammeter) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Generac NP-30G →
Source: Generac service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.