POWERMASTER JD377RN Alternator

( Brand: Powermaster ), ( Manufacturer Part Number: JD377RN ), ( Part Type: Alternator ), ( Manufacturer Warranty: 12 Month Warranty ), ( Info: Alternator 12si; 100 Amp; 75 Idle; 1 Groove V Type; Oe Look. ), ( Years: 1987 1988 1989 1990 87 88 89 90 ), ( Fitment: Gmc R3500 Alternator ), ( Cs-sku: 400 )

Review POWERMASTER Alternator Gmc fits R3500 1987–1990

Introducing the PowerMaster JD377RN, a top-tier replacement alternator specifically engineered for 1987 to 1990 GMC R3500 models with engines from 1988 and 1989. This alternator boasts an impressive balance of power and efficiency, ensuring your vehicle's electrical system remains robust and reliable.

This alternator is a direct-fit replacement for the original equipment, meaning it requires no modifications for installation. It comes equipped with a robust 135-ampere output capacity, ensuring your battery is consistently charged and your vehicle's electrical needs are met, even under heavy loads. The JD377RN alternator features a durable cast aluminum housing, which not only enhances its aesthetics but also provides excellent heat dissipation for optimal performance.

The alternator's internal components are engineered for long-lasting durability. It is equipped with a heavy-duty diode rectifier, which is designed to minimize power loss and provide a stable voltage output. The alternator also boasts a robust and reliable Voltage Regulator, which ensures precise voltage control for optimal battery charging and vehicle performance.

The PowerMaster JD377RN alternator is designed with a smooth and quiet operation in mind. Its double-sealed bearings and ribbed pulley reduce vibration and noise, providing a quiet and comfortable driving experience. The alternator also comes with a convenient 6-foot long power cable, allowing for easy installation and replacement of the original equipment.

In summary, the PowerMaster JD377RN alternator is a premium replacement option for 1987 to 1990 GMC R3500 models with engines from 1988 and 1989. Its impressive power output, durable design, and quiet operation make it an ideal choice for those seeking a reliable and efficient replacement alternator for their vehicle.

The Powermaster JD377RN alternator is a popular upgrade option for 1987-1990 GMC R3500 trucks with the 6.2L V8 engine. This alternator is known for its high output, durability, and ease of installation. Here are some pros and cons to help you decide if this alternator is the right choice for your vehicle:

1. Increased Power: The Powermaster JD377RN alternator produces 140 amps, which is significantly more than the original alternator. This increased output can help support additional electrical accessories and provide better charging performance.

2. Durability: Powermaster alternators are known for their robust construction, which includes a heavy-duty housing, high-output voltage regulator, and a strong drive belt. This alternator is designed to withstand the demands of heavy-duty applications.

3. Easy Installation: The Powermaster JD377RN alternator is a direct replacement for the original alternator, which means that it uses the same mounting points and wiring harness. This can save you time and money on installation costs.

4. Improved Charging: The high output of the Powermaster alternator can help keep your battery charged, even when running heavy electrical loads. This can help prevent premature battery failure and reduce the need for jump starts.

1. Cost: The Powermaster JD377RN alternator is more expensive than the original alternator. While the increased output and durability may be worth the investment for some, others may prefer a more cost-effective solution.

2. Size: The Powermaster alternator is slightly larger than the original alternator, which may require some modification to the engine compartment or the use of an extended drive belt.

3. Compatibility: The Powermaster JD377RN alternator is specifically designed for the 6.2L V8 engine found in 1987-1990 GMC R3500 trucks. It may not be compatible with other engine configurations or years.

In conclusion, the Powermaster JD377RN alternator is an excellent choice for 1987-1990 GMC R3500 trucks with the 6.2L V8 engine. Its high output, durability, and easy installation make it a popular upgrade option for those who require additional electrical power or want to improve their charging system. However, its cost and potential size requirements may be a concern for some. Ultimately, the decision to upgrade to the Powermaster alternator depends on your specific needs and budget. If you frequently use electrical accessories or want to ensure reliable charging performance, then the Powermaster JD377RN alternator is a worthwhile investment. If you have a limited budget or do not require the increased output, then a stock alternator may be a more cost-effective solution.

Details:

Most Popular Classic Look. Vehicle Fitment Information, Vehicle Engine, 1987 - 1990 GMC R35006.2L V8, R35007.4L 1987 - 1989 R35005.7L 1987 - 1988 R35004.8L 6 Cl. Individually Dino Tested with Proof of Performance Guarantee. One Unit For 1 Or 3 Wire Operation.

100 Plus Amps At Top End/75 Idle.

part #: jd377rn price

• $166.88

specifications altnagen:

• for makes: Gmc
• for years: 1987-1990
• brand: Powermaster
• mpn: Jd377rn
• part type: Alternator
• manufacturer warranty: 12 Month Warranty
• info: Alternator 12si; 100 Amp; 75 Idle; 1 Groove V Type; Oe Look.
• years: 1987 1988 1989 1990 87 88 89 90
• fitment: Gmc R3500 Alternator
• cs-sku: 400

returns altnagen:

• time: 30 Days
• paid by: Buyer
• policy: Returns Accepted

general altnagen:

• condition: New
• Car Truck Parts Accessories > Starters, Alternators, ECUs Wiring > Alternators Generators

offer altnagen:

• options: Ship-to-home
• quantity: 1
• availability: In Stock
• started: May 26, 2025
• sold: 0

seller altnagen:

• city: Dayton, New Jersey
• # reviews: 90739
• rating: 95.1%

shipping altnagen:

• cost: $0.00
• type: Fixed
• carrier: FedEx
• transit: 3-7 Days
• service: FedEx Ground or FedEx Home Delivery
• class: Standard

payments altnagen:

• credit card: Discover
• other
• wallet: Paypal

Powermaster JD377RN Is Similar To:

• 110 Powermaster Alternator Pulley Chrome 692209000136 (51.3% similar) Brand new pulley off of alternator requiring a serpentine instead...(March 17th, 2018)
• 17078 Powermaster Street Alternator (48.5% similar) 1g ford alternator 75 1 v pulley chrome...(April 3rd, 2018)
• 170781 Powermaster Alternator 692209001829 (56.6% similar) ...(January 15th, 2019)
• 17294-114 Powermaster Street Alternator Amps Chrome Plated Gm Case 692209004530 (44.8% similar) Advertised amperage output 100 amps alternator brackets included no case gm 12SI finish chrome plated belt notes 6-GROOVE pulley. One-wire capable yes pulley included serpentine quantity sold individually. Fitment information may not be available for all products and those without will have a ...(April 22nd, 2018)
• 17509 Powermaster Performance Alternator 692209001638 (54.7% similar) Powermaster alternator early Chrysler 75 double pulley field square back chrome features:excellent idle output heavy duty rectifier external regulator not included except one fireproof of performance tag manufacturer starters and alternators for racing show cars...(December 23rd, 2017)
• 175091 Powermaster Double Groove Pulley Alternator 692209001645 (47.2% similar) Shipping fast is important...(October 29th, 2018)
• 175191 Powermaster Performance Alternator 692209001669 (54.2% similar) Outdoor gear bikes, camping gear, etc. Powermaster alternator fits Chrysler square back 95 1v pulley 1 wire only chrome specifications:amperage: amp mounting: oem features:externally regulated heavy duty rectifier early oem retro look proof of performance tag Powermaster has a variety alternators ...(April 30th, 2018)
• 178611 Powermaster Street Alternator Amps Chrome Plated Gm Case 692209001867 (48.6% similar) Fitment information may not be available for all products and those without will have a compatibility link. Buyer pays return shipping. Advertised amperage output 105 amps alternator brackets included no case gm CS130 finish chrome plated belt one-wire capable yes pulley v-belt quantity sold ...(August 15th, 2018)
• 17864 Powermaster Street Alternator Amps Chrome Plated Gm Case Style (47% similar) Please feel free to call us at. Advertised amperage OUTPUT140 amps alternator brackets case style gm CS144ALTERNATOR finish chrome plated belt -wire individually...(November 1st, 2018)
• 2505047 Powermaster Xs Volt Drag Race Alternator Kit 692209007654 (46.5% similar) One-wire capable yes pulley included v-belt quantity sold as a kit. Advertised amperage output 55 amps alternator brackets included yes case poundings finish black powder coated belt notes snug mount bracket application for full body size vehicles. Buyer pays return shipping. Regulator included yes ...(May 1st, 2018)
• 27294 Powermaster Performance Alternator 692209001980 (51.3% similar) Powermaster alternator 12SI idle 1v oe look polished specifications:amperage: 100 amp mounting: oem features:ultimate custom billet at affordable prices smooth die cast housing w teardrop design smooth back special vents gold battery post proof of performance has a variety alternators available for...(April 16th, 2018)