1906 Moderate Moderate DIY

Generac Generator 1906 — Loss of AC Sense

Generac Generator · Error code 1906

What 1906 Means

Controller can no longer sense generator AC output even though engine is running. Often a wiring issue between the alternator and controller, or a failed sense circuit.

Symptoms

  • 1906 fault
  • Engine running but unit does not transfer
  • No AC voltage at the panel

Common Causes

1
Tripped main line circuit breaker on the generator

First thing to check — breaker on the side/back of the unit popped open.

2
Loose AC sense wiring at controller

Connector backed out of the controller.

3
Failed AVR

No output to sense.

4
Failed stator

Open or shorted stator winding.

How to Fix It

  1. Press the main line breaker on the generator firmly to OFF then back to ON.
  2. Power down, pull controller fuse, and reseat the AC sense connector at the controller.
  3. Measure AC output at the alternator with a multimeter while running in Manual — should be 240V at no-load.
  4. If 0V output, AVR or stator has failed — call dealer.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Main line circuit breaker View on Amazon→

More Generac Generator Codes

0000 0000 — No Active Alarm (Healthy) 1100 1100 — Low Oil Pressure Shutdown 1300 1300 — High Engine Temperature 1500 1500 — Overcrank 1501 1501 — Underspeed 1505 1505 — Overcrank (Variant — Try Again)

All Generac codes → All generator codes →

Verified against manufacturer documentation: generac.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.