One of the most frequent wiring questions is how to hook up the control for the Air Chime Whistle or Diesel Horn speakers that are in steam and diesel engines such as the 336 Northern, or most of the PA diesels. The explanation and diagrams below are taken directly from the original AF Instruction Manual.

Note, however, that 90% of the time, the plug-in canisters on the control units do not work without being opened, cleaned, adjusted, and resealed. Time has done its work, and the internal contacts are frequently worn, dirty, and/or oxidized. Proper adjustment is a little tricky, in order to get the horn to activate properly without slowing the engine appreciably. If you are not comfortable attempting this repair, we offer this service.

PARTS AVAILABILITY: Complete Air Chime Whistle Controls, with a guaranteed-OK plug-in generator: $25.00
(Note that the generator supplied may be a reconditioned unit.)

REPAIR: Send us your non-operating generator. We will repair and adjust it for you; $15.