2021 Freightliner MT Electrical Parts

Engine:

Showing parts for every engine. Select an engine to see only what fits.

This page lists 7 electrical parts for the 2021 Freightliner MT, across 2 part types, covering all 3 engine options (5.1L L4 DIESEL Turbocharged, 6.0L V8 and 6.7L L6 DIESEL Turbocharged). Every part shows its brand, manufacturer part number and fitment notes.

The electrical system on the 2021 Freightliner MT covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors. All 7 listed parts are Alternator / Generator (6 parts) and Starter Motor (1 part).

Alternator / Generator

Brand Part Number Markets Notes Buy
WAI GLOBAL Popular Fits: 5.1L L4 DIESEL Turbocharged 8681N
🇺🇸 US
Does Not Include Pulley
Fitment notes — WAI GLOBAL 8681N
Does Not Include Pulley
Detroit DIESEL Direct DRIVE5Leece Neville IR/EF 12V CWSupplied as 270 Amp without Pulley
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WAI GLOBAL Fits: 5.1L L4 DIESEL Turbocharged 8719N
🇺🇸 US
Does Not Include Pulley
Fitment notes — WAI GLOBAL 8719N
Does Not Include Pulley
Delco 24SI HP 12V CWSupplied as 160 Amp without PulleyDetroit DIESEL Direct DRIVE5
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WAI GLOBAL Fits: 5.1L L4 DIESEL Turbocharged 8741N
🇺🇸 US
Does Not Include Pulley
Fitment notes — WAI GLOBAL 8741N
Does Not Include Pulley
Delco 28SI 12V CW 160 To 200 AmpSupplied as 200 Amp without PulleyDetroit DIESEL Direct DRIVE5
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WAI GLOBAL Fits: 5.1L L4 DIESEL Turbocharged 8614N
🇺🇸 US
Does Not Include Pulley
Fitment notes — WAI GLOBAL 8614N
Does Not Include Pulley
Delco 36SI HP Quad Pad Mount IR/EF 12V BISupplied as 170 Amp without PulleyDetroit DIESEL Direct DRIVE5
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WAI GLOBAL Fits: 5.1L L4 DIESEL Turbocharged 8912N
🇺🇸 US
Does Not Include Pulley
Fitment notes — WAI GLOBAL 8912N
Does Not Include Pulley
Detroit DIESEL Direct DRIVE5Prestolite Internally Regulated/External Fan 12V 220 Amp Clockwise without Pulley
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WAI GLOBAL Fits: 6.0L V8 14007N
🇺🇸 US 🇨🇦 CA
Denso 12V 150A CW S6General Motors
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This table covers the alternators that charge the battery and run the electrical load. Typical signs include dim lights at idle, a battery lamp, or a growl from the charging pulley. Load-test the battery and inspect the belt and grounds — a bad ground mimics a failed alternator.

Starter Motor

Brand Part Number Markets Notes Buy
WAI GLOBAL Fits: 6.0L V8 6971N
🇺🇸 US 🇨🇦 CA
12V 1.5KW CW 9T GGeneral Motors
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This table covers the starter motors that crank the engine. Typical signs include no motion, a squeal, or a motor that only runs on one speed. Confirm power, ground and the control module before replacing the motor.

Buying Electrical Parts for a 2021 Freightliner MT

On this vehicle, the electrical system covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors.

  • Match the engine first. Every electrical part here is engine-specific; each row shows which engine(s) it fits.
  • Read the notes on each row for position, trim and spec qualifiers before you order.
  • Where labor overlaps, clean or renew the battery terminals and grounds with any charging-system repair.
  • Cross-reference the manufacturer part number against your old part or a service-manual listing.

Start with the largest groups on this page: Alternator / Generator and Starter Motor .

Frequently Asked Questions

How many electrical parts fit the 2021 Freightliner MT?

Our catalog currently lists 7 electrical parts for the 2021 Freightliner MT across 2 subcategories and 1 brand, covering all 3 engine options (5.1L L4 DIESEL Turbocharged, 6.0L V8 and 6.7L L6 DIESEL Turbocharged). Each part is matched to the engine(s) it fits.

Do electrical parts differ between 2021 Freightliner MT engines?

Yes. Every electrical part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.

What are the signs of electrical problems on a 2021 Freightliner MT?

Common symptoms include slow cranking on cold mornings, a battery light that flickers, dim lights at idle, or a check-engine code pointing at a sensor circuit. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.

What should I replace at the same time?

Where labor overlaps, clean or renew the battery terminals and grounds with any charging-system repair.

What do the market flags (US, CA, MX) on each part mean?

They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Freightliner MT was originally sold in the US, the safest choice is a part marked for the US market.

How do I make sure a part fits my 2021 Freightliner MT?

First match the engine — each row shows which engine(s) the part fits. Then test before replacing — a failed alternator and a bad ground can look identical, and sensors are frequently condemned for wiring faults. The notes column carries position and trim qualifiers where they apply.

Other Parts for the 2021 Freightliner MT

Electrical Parts for Other Freightliner MT Years

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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.