Choosing a New Alternator for Your 2007-2012 Mitsubishi Eclipse
Keep your 4th generation Eclipse running strong by understanding its charging system and picking the right replacement alternator.
- Before replacing the whole alternator, check for a broken B+ terminal post, which can be fixed with a cheap repair kit (TSB-06-16-001).
- Oil leaks from the valve cover are a common cause of repeated alternator failure; fix any leaks before installing a new part.
- For aftermarket brands, Denso offers OEM-level quality, while Remy and BBB are reliable mid-tier options.
- A healthy alternator should produce 13.5 to 14.5 volts at the battery terminals with the engine running.
Is Your Eclipse Alternator Failing?
An alternator rarely fails without giving some warning signs. If you notice any of these issues with your 2007-2012 Eclipse, it's time to check the charging system. Ignoring them can leave you stranded when the battery finally runs out of power.
Common Symptoms of a Bad Alternator:
- Battery Warning Light: The most common sign is the battery-shaped light on your dashboard. This means the system's voltage has dropped because the alternator isn't charging properly.
- Dim or Flickering Lights: If your headlights and dash lights seem dim, flicker, or get brighter when you rev the engine, the alternator is likely struggling to provide steady power.
- Whining or Grinding Noises: A high-pitched whine or a grinding sound that changes with engine speed often points to bad bearings inside the alternator.
- Electrical Problems: Slow power windows, a radio that cuts out, or other strange electrical behavior can happen when there isn't enough power to go around. Some owners have reported ongoing electrical issues, sometimes requiring multiple alternator and battery replacements, which can also be caused by bad fuses or poor ground connections.
- Dead Battery: If your battery is new but keeps dying, the alternator is the most likely culprit because it's not recharging the battery as you drive.
Pro Tip: Check This Before You Buy
Mitsubishi issued a Technical Service Bulletin (TSB-06-16-001) for 2006 and newer Eclipses regarding a damaged B+ terminal post on the alternator. A loose nut can cause this post to overheat and break. Before you buy a whole new alternator, inspect this main power connection. Mitsubishi offers a repair kit (Part No. MD632008) that can fix this specific issue for much less than the cost of a full replacement.
Choosing the Right Aftermarket Alternator
When your original alternator fails, you have a choice between OEM and aftermarket parts. For a vehicle like the 2007-2012 Eclipse, a quality new aftermarket alternator offers a great balance of performance and value. Aftermarket parts are often just as durable as original parts but at a more affordable price. The standard alternator for both the 2.4L and 3.8L V6 Eclipse models is rated at 110 amps.
Aftermarket Brand Tiers for Your Eclipse:
- Top Tier (OEM Supplier Quality): Denso is a well-respected brand and often the original equipment manufacturer for many Japanese vehicles. Choosing a new or remanufactured Denso alternator is the closest you can get to factory quality, known for reliability and long life.
- Mid-Tier (Reliable Aftermarket): Brands like Remy and BBB Industries offer a solid combination of quality and value. They are well-known in the aftermarket for producing reliable rotating electrical parts. Remy is noted for its high-performance components.
- Standard Tier (Budget-Friendly): Brands like MPA (Motorcar Parts of America), which includes the Quality-Built line, provide a cost-effective solution. These parts meet original specifications and are a good option if budget is the main concern, but always ensure they come with a good warranty.
A Note on Remanufactured Parts
While many remanufactured alternators are rebuilt to high standards, quality can be inconsistent. It's not uncommon to get a faulty unit right out of the box. To protect yourself, buy from a reputable seller with a good warranty and have the alternator tested before or immediately after installation.
Cost of Replacing Your Eclipse Alternator
The price for a new aftermarket alternator for a 2007-2012 Eclipse typically ranges from about $150 to $230. Professional installation can add a significant amount to the total cost.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Alternator | $153.87 - $231.89 |
| Shop Labor | $128 - $188 |
| Total Professional Replacement | $442 - $610 |
Frequently Asked Questions (FAQ)
Are there any recalls on the 2007-2012 Eclipse alternator?
No, there are no specific NHTSA recalls for the alternator itself on the 2007-2012 Mitsubishi Eclipse. However, there was a related recall for the drive belt tensioner on some other Mitsubishi models, which could affect the alternator's function if the belt comes off, but the Eclipse was not listed in that specific campaign. Always check for TSBs, like the one for the B+ terminal, which can solve problems without a full replacement.
Is it hard to replace the alternator on a 4th Gen Eclipse?
The difficulty is moderate. For the 2.4L 4-cylinder engine, the job is fairly straightforward and can be done by a DIYer with the right tools. The V6 model can be more challenging due to tighter space. The process involves disconnecting the battery, releasing the serpentine belt tensioner, unbolting the electrical connections, and then removing the two main mounting bolts. The V6 has an automatic spring-loaded tensioner, while some 4-cylinder models have a manual tensioner.
What's the difference between the 2.4L and 3.8L V6 alternator replacement?
The main difference is access and the belt tensioner. The V6 engine bay is more cramped, making it harder to reach the alternator and its bolts. The 3.8L V6 uses an automatic tensioner, which requires a wrench or breaker bar to release tension. The 2.4L 4-cylinder has more room to work and may have a manual tensioner that needs to be loosened.
My new alternator failed right away. What could be the cause?
First, remanufactured parts can sometimes be faulty out of the box due to inconsistent quality control. Second, an underlying issue may be damaging the alternator. A common problem on these cars is an oil leak from the valve cover gasket dripping onto the alternator, causing it to fail prematurely. Always check for and fix oil leaks before installing a new alternator.
Technical Specifications
OEM Part Numbers: 1800A145 A3TG4891 A3TG4891AC A3TG4891ZC
Amperage: 110 Amps, Voltage: 12V, Pulley: 6-Groove Pulley
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.
- Mitsubishi Eclipse:
- 🛍️ Shop This Part
- Is Your Eclipse Alternator Failing?
- Common Symptoms of a Bad Alternator:
- Pro Tip: Check This Before You Buy
- Choosing the Right Aftermarket Alternator
- Aftermarket Brand Tiers for Your Eclipse:
- A Note on Remanufactured Parts
- Cost of Replacing Your Eclipse Alternator
- Frequently Asked Questions (FAQ)
- 🎟️ Get 5% Off