Johnson Service Bulletin #657 (Corrected, 1958) - Electrical Wiring for Lights and Horn

Issued September 10, 1958. Johnson Motors explains how to wire bow and stern lights and a horn without damaging the magneto ignition coils. Includes the original boat wiring schematic and key-switch terminal photograph, plus factory instructions for fused accessory connections and correct battery polarity.

Johnson Motors blue seahorse Service Bulletin letterhead
September 10, 1958SERVICE BULLETIN #657 - CORRECTED

ELECTRICAL - WIRING FOR LIGHTS, HORN, ETC.

Original Johnson boat wiring schematic with bow light, stern light, horn, starter control cable, junction box and battery
Factory key switch photograph showing white solenoid, black ignition, and green hot terminals

There are indications that some of you may be encountering a bit of difficulty when wiring for stern and bow light and perhaps a horn. This - by attempting to take the "hot" and return leads off the starting key switch back of the panel to find that the magneto ignition coils have literally "blown up" when manipulating the key. Reason - 12 volts "shot" thru the coils and they won't take it.

Take your leads for accessories from the terminal posts on the junction box provided for the specific purpose - with the generator installation see suggested wiring diagram. (Positive lead to switch; negative return). By using junction box terminal parts, the circuit is "fused" and also registers on the ammeter.

If no generator installation, run light & horn leads to positive or negative leads of battery - insert 20 amp in positive lead. Do not attempt "picking" up leads at key switch.

When wiring direct to the battery, be sure the positive lead runs to the light switches; negative return or ground. Return and ground leads must be negative to

(OVER)

avoid cross polarity and resulting electrolysis.

Further, if by chance it is found necessary to remove leads from the key switch to complete electrical "rigging" of some boats - BE SURE THE LEADS ARE RESTORED TO THEIR ORIGINAL POSITIONS TO AVOID DAMAGE TO COILS - See diagram.

Very truly yours,

JOHNSON MOTORS

Arvid Olson
Arvid Olson
Service Promotion Manager

Electrical service notes

Factory warning: Do not connect accessory loads to the ignition key switch. The magneto ignition coils can be damaged by battery voltage. Use the accessory junction box where provided, or a properly fused direct battery circuit as described in the bulletin.

The wiring diagram and key-switch photograph are retained as original factory illustrations. The bulletin is marked Corrected in the original.