Choosing the Right Ignition Coil for Your 1950 DeSoto S-14
Keep your classic DeSoto's spark strong and reliable with the correct new aftermarket ignition coil.
- The 1950 DeSoto S-14 requires a specific 6-volt, positive-ground ignition coil.
- Symptoms of failure include no-start, rough running, stalling, and backfiring.
- New aftermarket brands like Standard Ignition and Spectra are reliable replacements for the unavailable original parts.
- For best results, replace the points, condenser, cap, and rotor at the same time as the coil.
Is Your DeSoto S-14 Showing Signs of a Failing Ignition Coil?
An ignition coil from 1950 has worked hard for a long time. Heat and vibration are its biggest enemies, and over decades, the delicate wire windings inside can break down. Because your DeSoto relies on a single coil for all six cylinders, a failure will stop the entire engine. Look for these common symptoms that point to a weak or failing coil.
Symptoms of a Bad Ignition Coil
- Hard Starting or No-Start: The engine cranks over but won't fire up, or takes a very long time to start. This is a classic sign of a weak or dead coil.
- Engine Misfires or Runs Rough: The engine may sputter, shake, or feel uneven, especially when trying to accelerate.
- Stalling: The engine may suddenly shut off, particularly when it's hot. Heat increases resistance in a failing coil, which can cause it to stop working until it cools down.
- Backfiring: Loud popping from the exhaust can happen when unburned fuel enters the exhaust system because the coil isn't providing a consistent spark to burn it in the cylinders.
- Weak Spark: If you test for spark by holding a spark plug wire near the engine block, a weak, yellowish or orange spark points to a bad coil. A healthy coil produces a bright blue spark.
No Check Engine Light or Codes
Your 1950 DeSoto does not have an onboard computer or a "Check Engine" light. It cannot store diagnostic trouble codes (like P0351). Diagnosing problems on your S-14 requires observing the symptoms and testing the components directly.
Choosing the Right Aftermarket Ignition Coil
Original equipment (OEM) ignition coils for your 1950 DeSoto haven't been made in decades. While you might find a New Old Stock (NOS) Mopar part, they are rare and can be very expensive. For a car you want to drive reliably, a new aftermarket coil is the best choice. These modern parts are made with fresh materials and are designed to meet the needs of your vintage ignition system.
Your DeSoto S-14 has a 6-volt, positive-ground electrical system. You MUST use an ignition coil that is specifically made for this setup. Using a 12-volt coil will result in a very weak spark, and using a negative-ground coil can cause it to fail quickly.
Available Brands: Standard vs. Spectra
For your S-14, two common aftermarket brands are Standard Ignition and Spectra. Both are reputable manufacturers that produce reliable parts.
- Standard Ignition (SMP): Standard is a very old American company that has been making ignition parts for generations. Mechanics have trusted them for decades, and their parts are known for being dependable replacements that fit and work correctly. For classic American cars, Standard is often considered a go-to brand.
- Spectra: Spectra is another quality manufacturer that produces a wide range of automotive parts. They state their coils use 100% copper windings and are durability tested to meet original specifications. They are a solid choice and a common brand found at many auto parts stores.
Pro-Tip: While both brands are good, many long-time mechanics and classic car owners have a long history with Standard Motor Products and trust the name for ignition components on vintage American vehicles. Given the small price difference, choosing the brand you have the most confidence in is the best approach.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Coil | $28.62 - $38.58 |
| New Old Stock (NOS) OEM Coil | $100+ (if found) |
| Shop Labor for Installation | $50 - $100 |
Frequently Asked Questions
Is replacing the ignition coil a difficult job?
No, this is a very easy job for a DIY mechanic. The coil is typically mounted to the engine or firewall with a simple bracket. It involves disconnecting the battery, removing two or three small wires, and unbolting the bracket. The entire job usually takes less than 30 minutes with basic hand tools.
Do I need a ballast resistor with my new coil?
For a stock 1950 DeSoto S-14, you should use a 6-volt coil that does not require an external ballast resistor. The new aftermarket coils designed for your vehicle are made to work with the original wiring system.
Should I replace other parts at the same time?
Yes. The ignition coil is just one part of a system. For a reliable tune-up, it is highly recommended to also replace the points, condenser, distributor cap, rotor, and spark plug wires. These are all wear items. A new coil will not perform well if the other components are old and worn out.
What is the most common mistake when ordering this part?
The most common mistake is ordering a 12-volt coil or a coil designed for a negative-ground system. Your 1950 DeSoto is 6-volt positive-ground. Always double-check that the part description specifies it is for a 6-volt positive-ground system.
Technical Specifications
OEM Part Numbers: 1120522
Voltage: 6V, Electrical System: Positive Ground, Type: Oil-Filled Canister, Primary Connection: Threaded Studs, Secondary Connection: Socket.
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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.