Guide to the 1941-1947 Studebaker M16 Brake Light Switch
Keep your classic Studebaker's brake lights working safely with the right replacement switch.
- The 1941-1947 Studebaker M16 uses a hydraulic pressure switch for its brake lights, not a mechanical one at the pedal.
- Failure is a critical safety issue; do not drive the truck if the brake lights are not working.
- A new aftermarket switch from a reputable brand like Standard Ignition is the most reliable replacement option.
- Replacing the switch is a simple task, but you MUST bleed the brakes afterward to ensure safety.
Understanding the Hydraulic Brake Light Switch
If the brake lights on your Studebaker M16 stop working, the brake light switch is a common part to fail. On these vintage trucks, the switch is not a button near the pedal but a pressure-activated sensor located under the hood. This design was common for the era but can have reliability issues. The original-style hydraulic switches are known to fail, sometimes leaking brake fluid or requiring a lot of pedal pressure to turn the lights on. This means your lights might not activate during gentle stops.
Symptoms of a Failing Brake Light Switch
A bad brake light switch can cause several problems. The most obvious sign is when your brake lights do not turn on at all when you press the pedal. You might also notice the opposite problem: the brake lights stay on constantly, even when the truck is off, which can drain your battery. Sometimes, a failing switch will cause the brake lights to flicker or only work intermittently. Any of these symptoms indicate the switch likely needs to be replaced.
Safety First: A Critical Part
Driving without working brake lights is extremely dangerous and illegal. If you suspect your brake light switch has failed, you should not drive the vehicle until it is repaired. A non-functioning switch means drivers behind you will not know when you are stopping, which can easily cause a rear-end collision.
Choosing the Right Aftermarket Switch
Finding a new original equipment (OEM) brake light switch for a vehicle from the 1940s is nearly impossible. Fortunately, the aftermarket provides reliable solutions. For a simple but crucial part like this, a new switch from a reputable brand is the best and most practical choice.
Standard Ignition (Standard Motor Products): This is a well-established brand that has been making quality automotive parts for over 100 years. Their replacement switches, such as the SLS27, are designed to meet or exceed original specifications. They use durable materials like brass housings and copper alloy conductors to ensure a long service life and reliable performance. For a vintage truck like the M16, a Standard Ignition switch is a trusted and widely available option.
Pro Tip: Test Before You Replace
Before buying a new switch, you can perform a simple test. Locate the switch on the master cylinder and unplug the two wires. Carefully use a small jumper wire to connect the two terminals on the wire harness. If the brake lights turn on, the switch is bad. If they don't, the problem is likely a blown fuse, bad bulbs, or an issue in the wiring itself.
Replacement Cost for a 1941-1947 Studebaker M16
The cost to replace the brake light switch is reasonable. The part itself is affordable, and if you have it done at a shop, the labor is minimal.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Switch | $38.97 |
| Shop Labor | $100 - $180 |
| Total Estimated Cost | $139 - $219 |
Frequently Asked Questions (FAQ)
Where is the brake light switch located on my Studebaker M16?
The brake light switch is a hydraulic pressure switch, not a mechanical one inside the cab. You will find it screwed into the master cylinder or a nearby brake line junction block under the hood. It will have two wires connected to it.
Do I need to bleed the brakes after replacing the switch?
Yes. Because the switch is part of the hydraulic brake system, you will introduce a small amount of air when you unscrew the old one. You must bleed the brakes after installing the new switch to remove this air and ensure your brakes function safely.
Is this a difficult part to replace myself?
For a DIY mechanic comfortable with basic tools and brake bleeding, this is a straightforward job. The main steps are unplugging the wires, unscrewing the old switch, quickly installing the new one to minimize fluid loss, and then bleeding the brake system.
Are there any recalls for the brake light switch on a Studebaker M16?
No, there are no recalls or Technical Service Bulletins (TSBs) from the National Highway Traffic Safety Administration (NHTSA) for the brake light switch on this vehicle. This is normal for a truck of this age, as the NHTSA's recall system was established much later.
Technical Specifications
OEM Part Numbers: 666858
Type: Hydraulic Pressure Switch, Activation: Screw-In, Terminal Type: 2-Terminal Bullet.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.