Product Manual

Generator Auto Start Requirements and Types
B–4 975-0307-01-01
Three-Wire Onan
The three-wire “Onan” starting type is suitable for generators that are not
as automated as the two-wire type. It requires a minimum of three wires:
a common wire, a start wire and a stop wire. You may also need to
connect the glow plug wires to Relay 1 (wire 14) or Relay 3 (wire 19). If
the generator requires independent control of the glow plugs, power may
also need to be run to Relay 3 (wire 20).
Identification
Generators of this type are controlled with a three-position switch that is
normally in a center (or neutral) position. To start the generator, the
switch is pressed and held to the start position until the generator starts.
The switch is then released, and it returns to the center position. To stop
the generator, the switch is pressed and held to the stop position until the
generator stops. Again, releasing the switch returns it to the center
position.
Connection
The common wire from the generator should connect to the common
connections of both Relay 1 and Relay 2 (wires 16 and 18 respectively).
The start wire from the generator connects to the normally open contact
of Relay 2 and the generator stop wire connects to the normally open
contact of Relay 1.