ID Model A Horns
There were 5 kinds of Model A Horns for 1928-1931. Most of the time they can be identified
by the brand stamped into the motor base. They can also be identified by the motor frame
width and the armature shaft diameter.
Stewart Warner
11/8" frame and 1/4" shaft
Caution: the nut on the end of the armature is a left handed thread
Sparton
3/4" frame and 1/4" shaft
GMI
1" frame and 5/16" shaft. The brush holder is unlike any other brand
EA
3/4" frame and 1/4" shaft
Ames
11/8" frame and 5/16" shaft
There were 5 kinds of Model A Horns for 1928-1931. Most of the time they can be identified
by the brand stamped into the motor base. They can also be identified by the motor frame
width and the armature shaft diameter.
Stewart Warner
11/8" frame and 1/4" shaft
Caution: the nut on the end of the armature is a left handed thread
Sparton
3/4" frame and 1/4" shaft
GMI
1" frame and 5/16" shaft. The brush holder is unlike any other brand
EA
3/4" frame and 1/4" shaft
Ames
11/8" frame and 5/16" shaft