Choosing an Alternator Upgrade for Your 1958-1962 Chevrolet Impala
Move beyond the original generator for a more reliable and powerful electrical system in your classic Impala.
- Upgrading your 1958-1962 Impala from its original generator to a modern alternator is a major reliability improvement.
- You will need a conversion bracket kit to mount the new alternator correctly on your engine.
- Choose an alternator with at least 60 amps for a stock car, or 100+ amps if you have added electrical accessories.
- For a stock appearance with modern performance, consider a Powermaster PowerGEN unit that looks like a generator.
Is Your Charging System Failing?
The charging system in your classic Impala, whether it's the original generator or an older alternator, gives clear signs when it's in trouble. A failing system can't keep the battery charged, which will eventually leave you stranded. Watch for these common symptoms.
🎬 Watch: A quick guide to identifying common alternator failure signs.Symptoms of a Bad Generator or Alternator
- Dim or Flickering Headlights: The most common sign is headlights that dim at idle and brighten as you rev the engine.
- "GEN" Light on Dash: Your Impala has a dashboard warning light for the generator. If this light comes on and stays on while driving, it indicates a problem.
- Dead Battery: A charging system that isn't working will not recharge your battery. You may find the car is difficult to start or won't start at all.
- Whining or Grinding Noises: Bad bearings inside the generator or alternator will make a distinct grinding or whining sound that changes with engine speed.
- Slow Electrical Accessories: Power windows or wipers that seem sluggish can be a sign of low voltage from a failing charging system.
Generator vs. Alternator: A Necessary Upgrade
The single best electrical upgrade you can make to your 1958-1962 Impala is converting from the factory generator to a modern alternator. Generators produce very little electricity at idle, which is why lights dim at stoplights. Alternators, however, produce significant power even at low engine speeds, making them far more reliable for any kind of driving. This upgrade is almost essential if you have added any modern electronics like a powerful stereo, electric cooling fans, or air conditioning. The conversion requires specific mounting brackets and some simple wiring changes.
🎬 See how to perform a complete generator to alternator conversion.Choosing the Right Aftermarket Alternator
When shopping for an alternator, you'll see different brands, power outputs (amperage), and styles. The right one for you depends on your car's needs and your budget.
What is a "One-Wire" Alternator?
Many aftermarket alternators for classic cars are called "one-wire" or "1-wire". This means they have an internal voltage regulator and only require a single wire connected from the alternator to the battery to function. This simplifies the wiring conversion from your old external generator regulator, making installation much easier.
Brand Tiers & Quality
- Top Tier (Performance & Specialty): Powermaster
Powermaster is a highly regarded brand in the classic and performance car community. They offer high-output alternators in various finishes to match your engine bay. Crucially, they also offer the "PowerGEN" series, which is a modern, high-output alternator built inside a case that looks exactly like your original generator. This is the perfect choice if you want modern reliability and power while keeping a completely stock look. 🎬 Watch: Installing a Powermaster alternator on a 1962 Chevy Impala.
- Mid Tier (Performance Value): Proform
Proform offers a wide range of alternators with high amperage outputs, often in chrome or black finishes. They are a popular choice for owners who need more power for accessories and want a custom look under the hood. They are known for being a good value and easy to install, with many one-wire options available. - Standard Tier (Replacement): ACDelco
ACDelco is a well-known brand for OEM and replacement parts. While they produce many reliable parts, reviews for their aftermarket alternators in classic car applications are mixed. Some users have reported premature failures or receiving defective units. While an option, the performance-focused brands often provide better results and reliability for this type of upgrade.
Amperage: How Much Power Do You Need?
The power output of an alternator is measured in amps. A stock generator produced around 30-40 amps. A basic alternator upgrade should be at least 60 amps. If you have added accessories like electric fans, a large stereo, or fuel injection, you will need more power. A 100-amp or higher alternator is a safe bet for most modified cars.
Cost of an Alternator Conversion
The cost can vary widely. You can buy just the alternator, or a complete kit that includes brackets and wiring. The price range for parts in our inventory is $7.42 to $583.93, with the lower end representing individual brackets and the higher end representing high-output, polished, or generator-look alternators.
| Item | Estimated Cost |
|---|---|
| New Aftermarket Alternator | $80 - $585 |
| Alternator Conversion Kit (Brackets, etc.) | $50 - $200 |
| Shop Labor for Conversion | $150 - $300 |
Frequently Asked Questions (FAQ)
Is an alternator really better than my stock generator?
Yes, absolutely. An alternator is more efficient, more reliable, and produces more electricity at idle than a generator. It is one of the most recommended reliability upgrades for any classic car that is driven regularly.
Do I need a special kit to install an alternator?
Yes, you will need a conversion kit or at least specific mounting brackets to physically bolt the alternator onto your engine in place of the generator. You will also need to make minor wiring changes to bypass the old external voltage regulator.
What amperage alternator should I buy?
For a stock or near-stock car, a 60-75 amp alternator is plenty. If you have added an electric fan, high-power stereo, or air conditioning, you should choose an alternator with 100 amps or more to handle the extra electrical load.
Will upgrading to an alternator hurt my car's value?
For most owners, no. An alternator conversion is a common and accepted upgrade that improves the car's usability and reliability. For a concours-level restoration aiming for perfect originality, it would be a deduction. However, you can use a Powermaster PowerGEN alternator which looks like a generator, giving you the best of both worlds.
Helpful Videos
Technical Specifications
Original Equipment: DC Generator. Aftermarket Upgrade: Alternator. Common Amperage Ratings: 60A, 75A, 100A, 150A. Common Regulator Type: Internal (One-Wire). Mounting: Requires conversion brackets.
We Have This Part in Stock
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.
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Charging System Failing?
- Symptoms of a Bad Generator or Alternator
- Generator vs. Alternator: A Necessary Upgrade
- Choosing the Right Aftermarket Alternator
- What is a "One-Wire" Alternator?
- Brand Tiers & Quality
- Amperage: How Much Power Do You Need?
- Cost of an Alternator Conversion
- Frequently Asked Questions (FAQ)
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