Ford's Roto-Selector: When You Changed the Radio With Your Foot

Today we have steering-wheel audio controls, touchscreens and voice commands. In 1941, Ford had another solution: Use your foot.

It sounds like an old-car tall tale until you see the period literature - and the installation instructions.

The Roto-Selector Radio Foot Control Switch was designed to let the driver operate the tuning system of a compatible Ford radio without reaching for the dashboard. C&G Ford Parts offers reproduction 11A-18934-A radio foot control switch with wire for applicable 1941-1948 Ford and Mercury passenger-car installations.

And this little switch is considerably more interesting than it looks.

Ford Really Called It the "Roto-Selector"

That name isn't something modern parts sellers dreamed up.

Ford's own 1941 promotional material advertised a new Ford radio with "Roto-Selector Control for fast automatic tuning." Period Lincoln literature also advertised an optional Roto-Selector Radio with foot control and long-distance antenna.

The original installation instructions supplied by C&G are headed "Roto-Selector Radio Foot Control Switch." Those instructions show the switch mounted on the floor between the clutch and brake pedals. Its electrical lead was routed up to the radio receiver and plugged into a socket provided on the receiver itself.

In other words, this wasn't an improvised accessory connected to an ordinary dashboard radio. The foot switch was designed to operate as part of the Roto-Selector radio system.

So What Did the Foot Switch Actually Do?

Here's where terminology matters.

The switch wasn't a modern SEEK control that searched the AM dial looking for the next strong signal. Instead, the Roto-Selector radio used preset stations.

Contemporary Zenith service information describes Roto-Selector tuning as allowing any five desired stations to be selected automatically using either the foot control or the Roto-Selector control on the instrument panel.

So when the driver operated the floor control, he wasn't telling the radio, "Go find me another station." He was telling it, "Move to another station I've already selected."

That's an important difference - and a pretty sophisticated feature for a car radio more than 80 years ago.

There Was More Going On Than a Simple Switch

The original C&G reference material also shows that the installation involved more than the button beneath the driver's shoe.

The accompanying diagram identifies a relay/circuit breaker assembly, wiring to the receiver, a radio suppressor identified as 11A-18827 / 09A-18827, and the associated mounting hardware.

That documentation is particularly useful because it shows us exactly where the reproduction 11A-18934-A fits into the larger system.

The foot switch was the driver's control. The antenna, radio receiver and its Roto-Selector equipment performed the tuning operation.

That's why saying the switch simply "changed the station" doesn't quite tell the whole story.

Why Control a Radio With Your Foot?

Think about manually tuning an automobile radio of the period. You're driving down a two-lane road while turning a tuning knob and watching a dial, trying to land precisely on the station you want.

Preset tuning eliminated much of that fiddling. Moving control of those presets down to the driver's foot meant the radio could be operated without reaching across the instrument panel.

It was an early solution to a problem automakers still work on today: How do you let the driver operate accessories while keeping attention on the road?

Different technology. Same problem.

Radio Was a Big Deal in the 1940s

It's easy to underestimate how important the radio itself was. There was no streaming audio, satellite radio or smartphone in your pocket. Radio brought drivers news, sports, music, weather and entertainment while they traveled.

American broadcasting was expanding rapidly. By June 30, 1948, the Federal Communications Commission reported 2,034 standard AM broadcast stations operating in the United States.

That's a far cry from the handful of choices we sometimes imagine when thinking about an old tube radio.

What Was Reception Like?

Those Ford radios operated in a very different broadcasting environment from today's digital entertainment systems.

AM reception depended on the station's frequency and transmitter power as well as distance, terrain, ground conductivity, interference and atmospheric conditions.

Nighttime could change everything. Medium-wave AM signals can propagate beyond their normal daytime range after sunset because radio energy can return to earth through the ionosphere. That made reception of distant stations possible - sometimes from hundreds of miles away. It could also produce fading and interference.

So the selection of stations available to a driver wasn't necessarily identical at noon and midnight.

Imagine heading down a highway after dark in your Ford. One of your regular stations starts fading as the miles roll by. Instead of leaning toward the dashboard and hunting around the dial, you've already got several stations adjusted into the Roto-Selector. Move your foot. Operate the switch. Bring up another preset.

Now the Roto-Selector starts making a lot more sense.

Five Presets Wasn't Primitive in 1941

Five stations may sound rather limited today. In 1941, it was convenience.

A Ford advertisement from the period specifically promoted the Roto-Selector as "fast automatic tuning." Contemporary Zenith service information confirms selection of five desired stations through the Roto-Selector system.

Instead of repeatedly finding a favorite station manually, the driver could have the desired stations preset.

That's essentially the same basic convenience provided by radio memory buttons for decades afterward - accomplished with vacuum tubes, switches and electromechanical hardware instead of microprocessors.

Did Every 1941-1948 Ford Have One?

No.

This is an important restoration distinction. Ford's own 1941 material describes the radio as an accessory, rather than standard equipment on every car.

An aftermarket replacement-part application covering several years does not prove that every Ford or Mercury radio built during those years originally used exactly the same switch or radio configuration.

C&G therefore lists 11A-18934-A for applicable 1941-1948 Ford and Mercury passenger-car applications. If you're doing a factory-correct restoration, the vehicle year and the radio equipment installed in the car should be considered.

The Kind of Detail That Makes a Restoration Fun

The Roto-Selector is exactly the sort of feature that makes an early Ford interesting.

Everybody notices the steering wheel. Everybody notices the gauges. But somebody eventually looks down at the floor and spots another switch.

"What's that?"

You point toward the radio. "Radio control."

Now you've got a conversation.

And with the original installation instructions available, we don't have to rely on somebody's recollection of how it supposedly worked. We can see where Ford intended the control to be installed, how its lead connected to the receiver, and how the system was laid out.

That's the difference between merely installing an old-car part and understanding the piece of history you're putting back into the car.

11A-18934-A Radio Foot Control Switch With Wire

C&G Ford Parts offers the reproduction 11A-18934-A Radio Foot Control Switch with Wire for applicable 1941-1948 Ford and Mercury passenger-car radio installations.

If you're restoring an original-style radio system and aren't certain whether your receiver uses the Roto-Selector foot control, contact us before ordering.

C&G Ford Parts has been helping enthusiasts keep classic Fords on the road since 1978, and our crew doesn't just sell old-car parts - we own and drive old cars ourselves.

Because sometimes the smallest part under the dashboard has one of the best stories in the whole car.

And yes - in 1941, Ford really did let you operate the radio with your foot.

Sources & Further Reading

• C&G Ford Parts - 11A-18934-A Radio Foot Control Switch

• 1941 Ford promotional literature - Roto-Selector automatic tuning

• 1941 Lincoln-Zephyr brochure - Roto-Selector Radio with foot control

• Zenith service data - Roto-Selector tuning and five-station selection

• Ford News index - period reference to Mercury Roto-Selector foot control

Primary material supplied by C&G Ford Parts: "Roto-Selector Radio Foot Control Switch" installation instructions, including mounting and wiring diagrams.