Parts / Alternator
Used Alternator for Medium-Duty Trucks
Alternators tested under load — the fix for battery lights, dimming and dead batteries on route.
- Used OEM part
- Tested before shipping
- 30-day warranty
- Ships to the lower 48
- Refundable core
A battery light or a dash that dims at idle isn’t a battery problem for long. Medium-duty trucks run big electrical loads — lift gates, reefers, lights, HVAC — and a failing alternator strands a truck on a route with dead batteries and a driver on the phone. New OEM alternators are pricey; cheap aftermarket units fail in months under commercial duty.
We supply used OEM alternators from running donor trucks, tested for output and diode ripple, with the correct pulley and connector for your engine. A refundable core charge may apply.
Signs your alternator has failed
- Battery or charging warning light on, or flickering at idle
- Headlights and dash dim at idle and brighten with RPM
- Batteries go dead overnight or after a short run — with new batteries
- Whine or growl from the alternator that changes with RPM
- Charging voltage under 13.2 V or over 15 V at idle
- Burnt smell, or a seized or wobbling pulley
Before you order
- Send your VIN and engine — output rating, mounting and connector change by engine and year; upfitted trucks may have a high-output option.
- Load-test the batteries and check cable ends and grounds first; a bad ground shows up as a charging fault.
- Inspect the belt and tensioner; a slipping belt kills output and the replacement’s bearings.
- On some trucks the ECM controls the alternator — verify the control circuit if a new unit won’t charge.
Select your truck for a alternator quote
Chevrolet
Mitsubishi Fuso
Related parts
Frequently asked questions
Which trucks do you stock a used Alternator for?
Isuzu NPR, NQR and NRR; Ford F-450 and F-550; Chevrolet Silverado and GMC Sierra 4500HD/5500HD plus Kodiak and TopKick C4500; Ram 4500 and 5500; and Mitsubishi Fuso Canter FE125–FE180. Pick your truck below or send us your VIN.
Is a used Alternator tested before it ships?
Yes. Every alternator we sell is pulled from a running donor truck, inspected and tested before it ships.
How do I get a quote for a used Alternator?
Use the form on this page or call us. Share your truck and VIN and we confirm exact fitment, then call you back with a price in about 30 seconds during business hours — or email it if we can’t reach you.
Is a used Alternator covered by a warranty?
Yes, we stand behind this alternator with our warranty. Exact terms are confirmed on your quote.
Do you ship a used Alternator nationwide?
Yes — we ship to all 48 contiguous states with tracked delivery. Most parts arrive in 3–7 business days; engines, transmissions and axles ship freight and typically arrive in 5–10.
Do you test used alternators?
Yes — every alternator is bench-tested for output and diode ripple before it ships.
How do I know it’s the alternator and not the batteries or starter?
Charging voltage at idle tells the story: under 13.2 V with good batteries is the alternator; a slow crank with a full charge is the starter. Our charging-system guide walks through the 15-minute check.
Is there a core charge on this Alternator?
This alternator may carry a refundable core charge, returned when your old unit is sent back within 30 days. Any core charge is stated clearly on your quote.