As with so many other items on these early trucks, there were also changes in the ignition switches. Both Chevrolet and GMC shared several switch changes during this seven-year series.
In the beginning (1947-1948), a unique three-position ignition cylinder and housing was introduced. This was a first for GM trucks. It related to a country with limited crime and a time when many people did not lock their houses. The switch allowed the truck to be started without a key.
By turning the cylinder and key to the far left, the ignition switch was locked. However, the middle position was the big difference! Here, the ignition was still off, but a small tab or teardrop extending down from the cylinder face allowed the driver an option. With a touch of a finger, you could turn the cylinder clockwise with or without a key using the teardrop. This 1947-48 feature was convenient for many owners, particularly on a farm. No longer did they worry about losing the key or having to dig when it was in a pocket.
When the key was moved to the far counterclockwise position, the ignition was locked. This security feature was built in. The switch could not be locked without the key, so no worry about it accidentally moving to the locked position.
This three-position switch was discontinued at the end of 1948 on trucks. GM then returned to the two-position on-off cylinder and housing that would not operate without a key. (1946 and older)
Between the years 1947-1953, the switch and cylinder combination, plus a one candle power bulb and socket was attached to a sheet metal housing. This assembly is screwed to the top of the lower inside dash lip out of sight. Only the round key cylinder face is seen by the driver. It extends through a larger hole in the dash. A resulting 1-1/16 inch circle opening between the dash and this cylinder face produces a lighted ring at night from the adjacent small bulb. This allows the driver to easily locate the switch in the dark. He only needed to pull the light switch to park position to see where to place the ignition key.
In 1954, with the redesigned dash, there was a complete change in the ignition switch housing. The threaded end of the die-cast housing is held in the dash by a chrome lock ring. Only this ring and the key cylinder face is visible to the driver. It is also a two-position on-off type as the key cylinder did not change.
With the introduction of the optional Hydramatic transmission in 1954, the switch did not change. The starter motor was activated by a button just below the headlight switch, not by the ignition key.
1947-48 Three Position – Never Produced
1949-53
This two-position switch replaced these earlier units (maybe even before the end of 1948). It offers the basic on/off by using the key only.
1954 – Early 1955 Ignition Switch with Rear Light Bulb Socket
A transition between 1949-1953, and the late 1955-59. A redesigned die-cast housing now uses a light bulb connection on the back side. It still has the three-wire connections with the on/off position. The stainless retaining nut is smaller than on the later design!
Late 1955-1959 Ignition Switch “Complete with Extras”
- Larger stainless retaining ring than 1954-Early 1955
- Lightbulb socket on the side
- Four electrical multi-connections
- Non-metal insert that moves the light down in the assembly to illuminate the ignition ring at night for seeing where to put your key