Model A, B, & V8
Ford Garage
Lighting Switch Handle and Horn Switch Assembly Rods
The pic above shows an original unrestored 1932 chrome plated Lighting Switch Handle and Horn Switch Assembly Rod.
This page details the Ford part numbers and lengths for the various familiar Model A style steering column light and horn switch rods used on 1928 through 1940 Model A & AA, Model B & BB, and later V8 era big trucks.
The original light and horn switch rod assembly consists of a nickel or chrome plated die-cast aluminum handle swaged onto a terne plated tubular steel rod.
The horn circuit ground wire is inside the tubular rod, and an insulated wire contact terminal is at the top and bottom of the wire in the tube.
The horn button is retained to the handle with a nickel or chrome plated round bezel with four bent toy-tabs on the back side. The button was produced in both nickel and chrome finish in 1928-29, and in black phenolic in 1930-40.
The spring loaded black phenolic horn button has an inserted steel contact plate which completes the electrical ground path between the horn wire upper contact terminal and the grounded switch handle, via the button spring.
The Model A has a relatively high amperage motor-driven horn, yet has no relay to handle the power delivered to the horn motor. Ford should have used a higher amperage relay to power the horn motor, while using the horn button circuit only as a relay signal.
Instead, Ford designed all motor current to pass through the switch itself. The higher current and resistance through the spring and its horn button contact is the weak link in the circuit.
The high current draw of the horn motor through the spring can and will overheat and anneal the spring if you have a heavy hand and like to lay on the horn button excessively.
A keeper groove (marked 'A') is located near the bottom of the rod, and a 'C-shaped' clip engages in the keeper groove retains the spring loaded spider to the rod. The spider engages and operates the light switch in the harness bulb (except for very early 1928).
Below the keeper groove and the rod end is a phenolic insulator which supports the lower contact terminal (marked 'B') soldered onto the bottom of the horn ground wire inside the tubular rod.
The dimensional data below was compiled from Ford-published Parts Price Lists and from original Ford drawing records at the Benson Ford Research Center in Dearborn.
| 1928 - 1929 Style ~ Lighting Switch Handle and Horn Switch Assembly Rods | |||
| Ford Part Number |
Overall Length B |
Keeper Length A |
Steering Gear, Shaft, & Column Usage Notes |
|---|---|---|---|
| A-3616-AR | ? | ~ | Early 1928, Ford 7-tooth, with 44-1/2" splined shaft, nickel plated (for non-spider, knurled light switch assembly housing) |
| A-3616-B | 46-5/32 | 45-3/4 | 1928-29, Ford 7-tooth, with 44-1/2" splined shaft, nickel plated |
| A-3616-C | 45-13/32 | 45 | 1929-30, Gemmer 2-tooth, with 43" splined shaft, nickel plated |
| A-3616-D | 46-5/32 | 45-3/4 | 1928-29, Ford 7-tooth, with 44-1/2" splined shaft, chrome plated |
| A-3616-E | 45-13/32 | 45 | 1929-30, Gemmer 2-tooth, with 43" splined shaft, chrome plated |
1930 - 1932 Style ~ Lighting Switch Handle and Horn Switch Assembly Rods (design style also has continued usage on later V8 era Trucks) | |||
| Ford Part Number |
Overall Length B |
Keeper Length A |
Steering Gear, Shaft, & Column Usage Notes |
| A-3616-F | 46-5/32 | 45-3/4 | 1930, Ford 7-tooth, with 44-1/2" splined shaft (January-June 1930 82-A cab trucks with 1930 style spoked steering wheel) |
| A-3616-G | 45-3/8 | 44-31/32 | *Early 1930, Gemmer 2-tooth, short column, with 43" keyed shaft, nickel plated |
| A-3616-H | 46-3/8 | 45-31/32 | 1930-31, Gemmer 2-tooth, long column, with 44" keyed shaft |
| B-3616 | 42-29/32 | 42-1/2 | 1932 Passenger & Commercial, Gemmer 3-tooth, chrome plated |
| BB-3616 | 43-31/32 | 43-9/16 | 1932-34 Model BB Truck, Gemmer 3-tooth, chrome plated |
| BF-3616-B | 44-17/32 | 44-1/8 | Forward Control Truck, chrome plated |
| 51-3616 | 44-9/16 | 44-5/32 | 1935-37 Model 51 big Truck, Gemmer 3-tooth, chrome plated |
| 70-3616 | 41-5/8 | 41-7/32 | 1938-40 141", 148.5", 168" big Truck, Gemmer 3-tooth, chrome plated |
| 81T-3616 | ? | ? | 1938-39 big Truck (normal control), Gemmer 3-tooth, chrome plated |
| 81Y-3616 | ? | ? | 1938-39 COE Truck (forward control), Gemmer 3-tooth, chrome plated |
*Note:
The early 1930 'short' Gemmer 2-tooth steering gear and column assembly was one inch shorter than the later common 1930-31 assemblies.That shorter length difference affected the light switch rod, the steering gear shaft, the column tube itself, as well as the spark and throttle control rod lengths. They are all shorter than the more common later versions.
Additionally, the early 1930 short gear and column assembly was used only with the early 1930 gas tank, which had a longer tank-mounted column support bracket. The steering wheel was lower in position relative to the driver's lap in the early 1930 models.
Later in 1930, Ford shortened the riveted gas tank bracket and stood the column more upright for added seat and leg room, and also lengthened the steering gear and column assembly itself to increase the distance between the steering wheel and the dash rail and windshield glass.
If you have an early short column assembly, but used with the later shorter riveted gas tank bracket, you may find your hands on the steering wheel uncomfortably close to the windshield and dash rail.
More related information on Ford Garage:
- For more Model A & B related information, use the Site Search box at the top or bottom of this page.
- Model A, B, & V8 Steering Shaft and Worm Gear Chart
- Model BB & 51 NOS 'Big Truck' Steering Wheel
July 2008