Choosing the Right Alternator for Your 1977-1987 Dodge W150
Keep your classic Dodge truck's electrical system reliable with the right new alternator.
- Charging problems are often caused by the external voltage regulator or wiring, not just the alternator.
- For stock trucks, a standard new aftermarket unit is sufficient. For trucks with added electronics, consider a high-output model.
- Symptoms include dim lights, a dead battery, whining noises, and a burning smell.
- Replacing the alternator is a DIY-friendly job for those with basic mechanical skills.
Is Your W150's Alternator Failing?
An alternator problem on these older Dodge trucks can show up in a few ways. Some signs are obvious, while others can be mistaken for other issues. Because these trucks use an external voltage regulator, sometimes the regulator or wiring is the real problem, not the alternator itself.
Common Symptoms:
- Dimming or Flickering Lights: Headlights and dash lights may flicker, or dim and brighten as you speed up or slow down.
- Battery Light: The 'BATT' or 'ALT' light on your dashboard may stay on while driving.
- Weak or Dead Battery: The alternator isn't recharging the battery, so your truck may struggle to start or not start at all.
- Strange Noises: A grinding or whining sound from the front of the engine can point to bad bearings inside the alternator.
- Electrical Problems: Power windows might move slowly, or the radio could cut out.
- Smell of Burning Rubber or Wires: A hot, burning smell could be a slipping alternator belt or melting electrical wiring. Some owners have reported issues with wiring melting near the alternator or at the firewall bulkhead connector.
Check the Voltage Regulator and Wiring First
Many charging problems on 1977-1987 Dodge trucks are caused by a failed external voltage regulator or bad wiring, not the alternator. A bad regulator can cause the system to overcharge (over 15 volts) or not charge at all. Before replacing the alternator, it's wise to check the wiring for corrosion and test the voltage regulator.
Choosing a New Aftermarket Alternator
Finding a brand-new OEM alternator from Mopar for a truck of this age is nearly impossible. The market is now dominated by new and remanufactured aftermarket parts. Here’s a look at the brands available and what to expect.
Brand Tiers for Your W150
- Performance (High-Output): Powermaster is a popular choice for owners who have added electrical accessories like winches, powerful stereos, or extra lights. They are known for providing more power at idle than standard units. While many users have good results, some have reported reliability issues, so they may be best for custom builds rather than daily drivers.
- Standard Replacement: Brands like BBB Industries, MPA (Motorcar Parts of America), and Remy offer direct-fit replacements that are a good balance of price and quality for a stock truck. Remy is a historic brand, though its aftermarket line is now associated with BBB Industries. Reviews for these brands are generally mixed, with some users experiencing early failures, often related to bearings. Buying from a retailer with a good warranty can provide peace of mind.
Pro Tip: When you replace your alternator, it's a good time to inspect the belt for cracks and wear. Also, check your battery terminals and ground wires for corrosion. A bad ground can cause charging issues that look like a faulty alternator.
How Much Does a New Alternator Cost?
The cost depends on the brand you choose and who does the work. For a 1977-1987 Dodge W150, prices are reasonable.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $85 - $153 |
| Remanufactured Aftermarket | $70 - $150 |
| Used OEM | $50 - $100 |
| Shop Labor | $98 - $143 |
Frequently Asked Questions
Do I need a high-output alternator?
If your W150 is mostly stock, a standard replacement alternator is all you need. If you have added high-power accessories like a winch, a large sound system, or off-road lights, a high-output alternator from a brand like Powermaster is a good investment to handle the extra electrical load.
What's the difference between an internally and externally regulated alternator?
Your 1977-1987 W150 came from the factory with an external voltage regulator. This is a separate part mounted on the firewall that controls the alternator's output. Some aftermarket alternators have an internal regulator built-in. While this can simplify wiring, it requires modifying your truck's original wiring harness.
Can I replace the alternator myself?
Yes, for most people with basic tools and mechanical skills, this is a manageable job. The alternator is usually easy to access on these trucks. The process involves disconnecting the battery, loosening the belt tensioner to remove the belt, unplugging the wires, and removing a couple of mounting bolts.
Are there any recalls for the alternator on my truck?
No, searches of the National Highway Traffic Safety Administration (NHTSA) database did not show any alternator-specific recalls for the 1977-1987 Dodge W150 model years.
Technical Specifications
The key specifications for a 1977-1987 Dodge W150 alternator are its amperage output (typically ranging from 60A to 100A for standard models), pulley type (V-belt), and whether it is designed for an external voltage regulator. Always verify fitment for your specific year and engine.
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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.