Dodge B150 Alternator Replacement Guide (1981-1987)
Everything you need to know about choosing the right new alternator for your classic Dodge van.
- For this van, the issue could be the external voltage regulator, not the alternator itself. Test both.
- A standard 60-amp new aftermarket alternator is the best choice for most stock B150s.
- Before ordering, always check your ground wires and battery connections for corrosion, as this can cause similar symptoms.
- This is a simple replacement you can likely do yourself in under two hours with basic tools.
Is Your B150's Alternator Failing?
An alternator rarely fails without warning. If your Dodge B150 is over 30 years old, its original charging system components are living on borrowed time. Watch for these common signs that your alternator is on its way out:
- Dimming or Flickering Headlights: This is one of the most common symptoms. You might notice the lights dim at idle and brighten as you rev the engine.
- Battery Warning Light: Your dashboard might have a battery icon, "ALT," or "GEN" light that illuminates when the system detects a charging problem.
- Slow or Malfunctioning Electronics: Power windows that move slowly, a weak-sounding radio, or other electrical oddities point to a lack of sufficient power.
- Whining or Grinding Noises: A high-pitched whine or a grinding sound from the front of the engine can indicate failing bearings inside the alternator.
- Dead Battery: The alternator is supposed to recharge your battery. If the battery keeps dying, the alternator is likely not doing its job.
Pro Tip: Check Your Connections First
Before you replace the alternator, check the basics. These vans are old, and electrical connections can become corroded or loose. Ensure the battery terminals are clean and tight. Inspect the ground wire from the engine to the chassis for rust or damage. A bad ground can mimic the symptoms of a failed alternator.
Choosing the Right Aftermarket Alternator
For a vehicle from this era, finding a brand-new OEM alternator is nearly impossible. The market consists of new aftermarket and remanufactured parts. For the B150, a quality new aftermarket unit is often the most reliable choice.
Brand Quality Tiers
Not all aftermarket brands are created equal. Here’s a breakdown of the brands available for your B150:
- Good - Standard Replacement (ACDelco, MPA, BBB Industries, Remy): These brands are the workhorses of the aftermarket.
- ACDelco: A well-regarded brand with a history tied to GM, known for consistent quality.
- MPA (Motorcar Parts of America): A major manufacturer that produces parts under the "Quality-Built" brand, emphasizing strict testing.
- BBB Industries: A large remanufacturer that supplies many auto parts stores. Their quality is generally considered decent for remanufactured parts.
- Remy: Reviews for Remy are often mixed. While some have no issues, others report premature failures like bad bearings within a year.
- Best for Performance (Powermaster): If you've added high-draw accessories like a powerful stereo, extra lights, or a winch, a high-output alternator is a smart upgrade. Powermaster specializes in these units, which provide more amperage, especially at low engine RPMs. While they are a performance upgrade, some users have reported noise or reliability issues, so they may be overkill for a stock van.
Cost of Replacing Your B150 Alternator
Here are typical cost ranges you can expect. Prices vary based on brand, warranty, and your location.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Alternator | $76.84 - $152.39 |
| Remanufactured Alternator | $94.00 - $202.00 |
| Used OEM (Junkyard) | $50 - $100 |
| Shop Labor | $122 - $179 |
| Total Professional Replacement | $200 - $331 (using aftermarket part) |
Frequently Asked Questions
Can I replace the alternator on my Dodge B150 myself?
Yes, this is a very DIY-friendly job for someone with basic mechanical skills. The alternator is usually located at the top front of the engine and is easy to access. The process involves disconnecting the battery, loosening the drive belt, removing a few bolts and electrical connectors, and swapping the part. The entire job can typically be done in 1-2 hours with standard hand tools.
Do I need a high-output alternator?
For a stock Dodge B150, the standard 60-amp alternator is usually sufficient. You should only consider a high-output model (100+ amps) if you have added significant electrical loads, such as a large audio system, a winch, or extensive auxiliary lighting. Installing a high-output alternator on a stock vehicle will not cause any harm, but it is not necessary.
What is an external voltage regulator and do I need to replace it?
Many Chrysler vehicles from this era used a voltage regulator mounted separately from the alternator, often on the firewall. Its job is to manage the alternator's output. Sometimes, the regulator fails, not the alternator itself. If you replace your alternator and still have charging problems, the external regulator is the next component to test and likely replace. It is much cheaper than an alternator.
What's the difference between New and Remanufactured?
A new alternator is made with 100% new components. A remanufactured alternator is a used OEM core that has been disassembled, cleaned, and rebuilt. Worn parts like bearings and brushes are replaced, but the core housings are reused. While remanufactured parts can be a good value, their quality can be inconsistent. For a critical component like an alternator, a new aftermarket part often provides better peace of mind for a similar price.
Technical Specifications
OEM Part Numbers: 3438807 3656451 3656615 3755403 3755407 04091565 04176007
Standard output is typically 60 amps with a single V-groove pulley. These models use an external voltage regulator. High-output options are available.
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.
- Dodge B150: