Cummins Onan · HGLAA and compatible controllers; verify model applicability

Code 13Output under voltage

Generator output voltage fell below the controller's protection limit and the set shut down.

Published by RV Fault Finder · Independent referencePrimary source checked August 2026How this guide is researched →

What it means

Plain-English answer

The controller could not maintain adequate output voltage. Loads can contribute, but internal generator or regulation faults need professional diagnosis.

Owner-safe checks

What to check first

01
Disconnect all RV loads before any restart.
02
Confirm fuel supply and exterior cooling airflow.
03
Note whether the fault occurs unloaded or when a specific appliance starts.

Safety boundary

Stop and call a technician when

The fault returns with all loads disconnected.
Lights flicker severely or connected equipment behaves abnormally.

Primary reference

Check the exact manual

Applicability: HGLAA and compatible controllers; verify model applicability. The data plate and specification letter determine which procedure is correct.

Open Cummins Onan HGLAA operator manual ↗Source reviewed August 2026