Alternator for Thermo King LND 50, SB-190, SB-200, SB-300, SB-310 BOS-AL9120N

Alternator for Thermo King LND 50, SB-190, SB-200, SB-300, SB-310 BOS-AL9120N

Item #: BOS-AL9120N

30-DAY RETURN POLICY

If your order arrives and it’s not exactly what you want, you may return it within 30 days for a refund. We know that people sometimes order a part and then discover it’s not exactly the one they need for the repair. We understand and want to work with you. Just make sure the item is in its original packaging and in good condition free of damage.

When a returned product comes back to us, we’ll check it over to make sure it’s in ‘Like New’ condition and free from damage such as dents, scratches, cracks, abuse, defacement or indication of removed screws/fasteners or seals. Return processing may take up to 5 business days from the time your product is received by DB Electrical.

To return a product, simply click here to start the process.

Order today to get this price.

$508.96 $300.15
Next Day Air Shipping for
Order today and ships out next business day.
Order in the next hrs mins secs
Mechanics Choice: OEM performance at a money-saving price.
  • 100% New aftermarket unit built to meet OEM specifications
  • 1-year warranty protects you after your purchase
  • Factory direct pricing with no middleman markup delivers exceptional value
Check if this fits your vehicle
HOW TO FIND YOUR FITMENT
Two ways to ensure proper fitment
DO YOU KNOW YOUR
OEM PART NUMBER?
Look for your OEM part number below or use our search tool.
LOOK FOR YOUR
MAKE/ MODEL/ YEAR
Enter your make/model/year below to find the right part.
  • Product Info
  • Applications List
  • Part Replacement List
  • Policy Information
  • Reviews

Overview

Fast shipping and the lowest prices.
Find the right part for your make and model at DB Electrical.

Item Number: BOS-AL9120N

100% Brand New Aftermarket Part From DB Electrical

Product Specs

Item ConditionAftermarket Part
DescriptionAlternator
Volt12
Amps120
ConditionNew
Regulator Clock12:30
Rotation DirectionClockwise
Mount Hole ID 1M8x1.25
Mount Hole 1 TypeThreaded
Mount Hole 2 TypeUnthreaded
Mounting Ear Thickness0.787"
Mounting Ear Thickness20mm
Mounting Ear 2 Thickness1.996"
Mounting Ear 2 Thickness50.700mm
Fan LocationExternal
Regulator LocationInternal
Terminal ID 2B+
Terminal 2 SizeM6x1.00
Terminal ID 3L
Terminal 3 SizeSpade
Terminal ID 4S
Terminal 4 SizeSpade
Terminal ID 5W
Terminal 5 SizeSpade
PolarityNegative
Shaft Pulley OD0.669"
Shaft Pulley OD17mm
ShaftM16x1.50

Applications List

Select Make & Type
MAKE TYPE MODEL YEAR ENGINE
Thermo KingLND 50 Yanmar 353 (TK 3.53) Diese
Thermo KingSB-190 Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSB-200 Yanmar 486 (TK 4.86) Diese
Thermo KingSB-210 Yanmar 486 (TK 4.86) Diese
Thermo KingSB-300 Yanmar 486 (TK 4.86) Diese
Thermo KingSB-310 Yanmar 486 (TK 4.86) Diese
Thermo KingSB-II MAX Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSB-II SR Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSB-II SR Yanmar 486 (TK 4.86) Diese
Thermo KingSB-II
Thermo KingSB-III MAX Isuzu 2.0L (TK C201) Diese
Thermo KingSB-III MAX
Thermo KingSB-III SR Yanmar 486 (TK 4.86) Diese
Thermo KingSB-III SR Yanmar 486 (TK 4.86) Diese
Thermo KingSB-III SR Yanmar 486 (TK 4.86) Diese
Thermo KingSB-III SR
Thermo KingSB-III
Thermo KingSDZ Kubota Z400 Diese
Thermo KingSDZ
Thermo KingSentry Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSL100 Yanmar 482 / 486 (TK 4.82 / 4.86
Thermo KingSL100e Yanmar 486 (TK 4.86) Diese
Thermo KingSL200 Yanmar 482 / 486 (TK 4.82 / 4.86
Thermo KingSL200e Yanmar 486 (TK 4.86) Diese
Thermo KingSL300 Yanmar 482 / 486 (TK 4.82 / 4.86
Thermo KingSL400 SR2 Yanmar 486 (TK 4.86) Diese
Thermo KingSL400 Yanmar 482 / 486 (TK 4.82 / 4.86
Thermo KingSL400e Yanmar 486 (TK 4.86) Diese
Thermo KingSMX II
Thermo KingSMX SR
Thermo KingSMX
Thermo KingSuper II SR Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSuper II TC Isuzu 2.2L (TK DI2.2 -SE) Ds
Thermo KingSuper II TC Yanmar 486 (TK 4.86) Diese
Thermo KingSuper II TC Yanmar 486 (TK 4.86) Diese
Thermo KingSuper II TC Yanmar 486 (TK 4.86) Diese
Thermo KingSuper II

Replaces These Part Numbers

ArrowheadBAL9120N
Bosch0120484028, AL9120N, AL9120X, F005A00020
J&N Electrical Products400-24042
Leece NevilleAK1120
Thermo King20-41-5457, 41-5456, 41-5457, 5D50461G01

Frequently Asked Questions

Q: Do I need a larger charge wire for a High Output unit?
A: The high amp unit will operate better than stock, but not to its full potential without a larger charge wire. It’s the same reason firetrucks do not use garden hoses. It is IMPARATIVE to have proper charge and ground cables.

Q: Does a High Amp unit cause any damage to my battery or my vehicles charging system?
A: As long as it is installed properly with battery in good condition, then no. A High Output unit works exactly like a factory unit and only produces what is being demanded. No alternator works continuously at full output. Higher amperage is not bad and will not hurt a battery, but high voltage will blow one up.

Q: Will aftermarket underdrive pulleys (crankshaft power pulley) have any effect on my alternator?
A: Yes, underdrive crankshaft pulleys slow all the components (power steering, a/c, and alternator) to provide more power to the rear wheels. In some cases, the charging systems will fall totally on the battery at idle and completely stop charging.

Q: Where is the best place to get a voltage reading of the alternator output?
A: You’ll get the most accurate voltage reading from the back of the alternator at the main charge post that runs directly to the battery. This must be done while the vehicle is running.

Q: Why is the pulley on a high amp alternator smaller than my stock pulley?
A: The smaller pulley advances the power curve of the alternator just slightly, which produces a little more amperage around the idle if needed.

Q: Will I need a smaller belt for my high amp unit?
A: This varies by application because not all belts and belt tensioners are in the same condition. The tensioner will always tell you if you need a new belt or not. If it’s in range, you will not. If it is out, you will. Generally, you will need a belt that is one inch shorter than stock. You should have no problem finding a replacement wherever you buy your parts. V belt applications simply re-adjust your belt tensions to 3/8” deflection.

Q: What is the difference between a one wire, self-exciting and a self-energizing regulator?
A: Nothing. They are all exactly the same. Different manufacturers use different terms for marketing. The only wire to hook up is the charge wire to the battery. This does require modification for the alternator charge light on the dash.

Q: My stock unit used a five-groove pulley, and you sent my high amp alternator with a 6 groove. Why and what can I do?
A: 5 groove overdrive pullies are not produced. Install the belt on the back groove of the pulley closest to the fan or body of the alternator. The fan is internal, and this application will work just fine.

Q: Can your alternator be run in dual or triple alternator applications?
A: Yes. When wired and mounted correctly, the alternator can run in either dual or triple applications.

Q: Will I need a new battery with a high amp alternator?
A: If your battery is in good condition, and in spec of its OEM rating, then no. Your battery should work equally well with either the OEM and a High Amp unit.

Customer Reviews

WARNING: California’s Proposition 65

Recommended Products

Keeping customers satisfied for over 35 years.

Customers keep returning because we keep delivering total satisfaction. Our key to success is selling parts that fit and perform like the originals. It's why so many mechanics make us their top choice.

  • Find The Right Part

    Use our advanced part finder or search by part number to find your part.

  • Same-Day Shipping

    Orders placed by 2pm EST will ship that same day.

  • Fast, Free Delivery

    Orders over $50 shipped FREE to the 48 adjoining U.S states.

  • Expert Advice

    Need help choosing your part? Please contact us for help.

Back To Top