Updated June 2026
AC Belt, Alternator Belt & Accessory Belt Replacement Cost
If you searched for the cost to replace your AC belt, alternator belt, accessory belt, or air conditioner belt, here is the answer most people do not expect: on almost every vehicle built since the early 1990s, these are all the same single belt. It is called the serpentine belt, and one belt drives every engine accessory at once.
The Short Answer
Replacing the AC belt, alternator belt, or accessory belt costs $100-$250 at a shop because on the vast majority of vehicles it is the serpentine belt. The belt part is $25-$75; labor is the rest. With the tensioner bundled in, expect $150-$400.
The exception: a minority of vehicles, mainly some trucks, vans, and certain 1990s-2000s models, use a separate smaller belt dedicated to the AC compressor. Replacing just that belt usually runs $50-$150 depending on how accessible it is.
What You Searched For vs What It Actually Is
These search terms all describe the same repair on a modern vehicle. The belt got a different nickname depending on which accessory the driver noticed first when it failed.
| If you searched for | On a modern vehicle it is | Typical cost |
|---|---|---|
| AC belt replacement cost | The serpentine belt (it drives the AC compressor) | $100-$250 |
| Alternator belt cost | The serpentine belt (it drives the alternator) | $100-$250 |
| Accessory belt replacement cost | The serpentine belt (it drives all accessories) | $100-$250 |
| Air conditioner belt replacement cost | The serpentine belt, or a separate AC belt on some vehicles | $100-$250 |
| AC compressor belt replacement cost | Usually the serpentine belt; a dedicated AC belt on a minority of vehicles | $100-$250 |
| Power steering belt cost | The serpentine belt (it drives the power steering pump) | $100-$250 |
See the full list of belt names and why one belt has so many.
AC / Alternator / Accessory Belt Cost Breakdown
| Scenario | Part | Total |
|---|---|---|
| Single serpentine belt (almost all vehicles) | $25-$75 | $100-$250 |
| Serpentine belt + tensioner | $55-$195 | $150-$400 |
| Separate dedicated AC belt (minority of vehicles) | $15-$45 | $50-$150 |
| DIY single serpentine belt | $25-$75 | $25-$75 |
Estimates for US independent shops. Dealerships add 20-40%. See the full cost estimator for a vehicle-specific number.
When the AC Belt Is a Separate Belt
On the vast majority of cars and light trucks built since the early 1990s there is no separate AC belt. One serpentine belt drives the AC compressor along with everything else, so "AC belt replacement" means replacing that serpentine belt.
A small number of vehicles, mainly some trucks, vans, and a handful of 1990s-2000s models, use a two-belt setup: the main serpentine belt drives most accessories, and a second, smaller belt drives the AC compressor on its own. If your vehicle is one of these, replacing only the AC belt is usually cheaper than a full serpentine belt because the belt is smaller, but the labor depends entirely on how easy that belt is to reach.
How to tell which you have: open the hood and look at the AC compressor (a pump with thick refrigerant lines running to it). Trace the belt around it. If the same wide, multi-ribbed belt also wraps the alternator and crankshaft pulley, you have a single serpentine belt. If a separate, smaller belt loops only between the AC compressor and the crankshaft, you have a dedicated AC belt.
Do Not Confuse the AC Belt With the AC Compressor
If your AC stopped blowing cold, the belt is the cheapest possible cause and worth checking first. The belt is the rubber loop that spins the compressor. The compressor is the pump it spins.
AC belt
$100-$250
The serpentine belt that drives the compressor. Cheap, fast.
AC compressor
$500-$1,200+
The pump itself. A major repair if it has failed.
A slipping belt often affects the AC first because the AC compressor has the highest load of any accessory on the belt. If the belt is intact and properly tensioned, the fault is elsewhere. The dedicated AC Compressor Replacement Cost guide covers the scenario where the compressor itself has failed.
Frequently Asked Questions
How much does an AC belt replacement cost?
On the vast majority of vehicles the AC belt is the serpentine belt, so replacement costs $100-$250 at a shop, or $25-$75 in parts if you do it yourself. The serpentine belt drives the AC compressor along with the alternator and power steering. If your vehicle is one of the few with a separate, dedicated AC compressor belt, replacing only that belt usually runs $50-$150 depending on how accessible it is.
Is the AC belt the same as the serpentine belt?
On almost all vehicles built since the early 1990s, yes. One serpentine belt drives every engine accessory including the AC compressor, so the AC belt, alternator belt, accessory belt, and serpentine belt are all the same part. A minority of vehicles, mainly some trucks, vans, and certain 1990s-2000s models, use a second smaller belt dedicated to the AC compressor.
How much does an alternator belt cost to replace?
The alternator belt is the serpentine belt on modern vehicles, so replacement costs $100-$250 at a shop. The belt itself is $25-$75. If the battery light came on and you also notice belt squeal or heavy steering, the serpentine belt is the likely cause because it drives the alternator, AC, and power steering together.
What is the difference between the AC belt and the AC compressor?
The belt is the cheap rubber part that spins the compressor, costing $100-$250 to replace. The AC compressor is the pump itself, costing $500-$1,200+ to replace. If your AC stopped working, the belt is the first and cheapest thing to check before assuming the compressor has failed.
Does replacing the serpentine belt fix the AC?
Only if the belt was the cause. A slipping or broken serpentine belt stops the AC compressor from spinning, so a new belt restores AC in that case. If the belt is intact and tensioned correctly, the problem is elsewhere: a failed compressor, low refrigerant, or an electrical fault.