Can a bad serpentine belt cause AC not to work?

Author: Prof. Loy Tillman  |  Last update: Thursday, October 30, 2025

Loss of Power Steering or Air Conditioning As the serpentine belt drives the power steering pump and air conditioning compressor, a failing belt can result in a sudden loss of power steering assistance or reduced cooling capacity from the air conditioner.

Can a bad belt cause AC not to work?

Yes. If the fan belt is lose, the compressor pully may slip and will not run in full capacity and will affect the output.

What are the symptoms of a bad serpentine belt?

Bad serpentine belt symptoms
  • Squeaking, squealing or chirping sound from under the hood of the car.
  • Check engine light or battery light is illuminated on your dashboard.
  • A/C isn't working.
  • Power steering isn't working.
  • The engine's temperature is high or overheating.
  • Smell of burnt rubber.

What belt runs the AC compressor?

Older vehicles use v-belts, which generally only run the AC compressor. As the name suggests, it is V-shaped and narrow. Newer vehicles use serpentine belts, which are flat and ribbed to run all the engine components, including the drive belt.

Can a bad serpentine belt affect acceleration?

While a bad serpentine belt might not directly affect the engine's ability to accelerate, it can indirectly impact performance. If the belt fails and the alternator stops charging the battery, the resulting electrical problems could affect the vehicle's overall performance, including acceleration.

SYMPTOMS OF A BAD SERPENTINE BELT

Can my serpentine belt cause loss of power?

Diminished Performance and Other Symptoms

Some serpentine belt issues may not cause your vehicle to stop running or overheat, but they can create other symptoms that point to belt failure. You may notice a loss of performance, power steering failure, sudden battery drain, or a loss of air conditioning.

Does a fan belt affect air conditioning?

Belt damage is a common issue with air-conditioning systems, as the belt plays an integral role in keeping the system running smoothly.

What belt controls the air conditioner?

As we mentioned early, a serpentine belt delivers power to your alternator, power steering pump, and air conditioning compressor.

Will a bad AC compressor break serpentine belt?

Your compressor can seize, causing the belt to snap.

How do I know if my AC compressor belt is bad?

Noises coming from the engine compartment

A squealing belt, a whining power steering pump, a worn out pulley, brake pads in need of replacement. If, on inspection, you hear chattering, whining, squealing, chirping, or rattling sounds coming from the AC compressor, it is time for AC service.

How do I know if my serpentine belt needs replacing?

Visible Cracks and Wear

Regular visual inspections of the serpentine belt can reveal important information about its condition. If you notice cracks, fraying, or signs of wear on the belt's surface, it's a clear indication that it needs replacement.

What are the signs of a bad alternator?

How Do You Know if a Car Alternator is Bad?
  • Trouble starting your car.
  • Frequent stalling.
  • Whining or screeching noise after the vehicle starts.
  • Dim or overly bright lights.
  • Smell of burning rubber or wires.
  • Dead battery.
  • Battery dashboard warning light is on.

Will my car run with a bad serpentine belt?

Technically, you can drive your vehicle - but, ideally, to the nearest auto repair shop or back home to fix the issue yourself.

How much does it cost to replace a serpentine belt?

Of course, like any other rubber component, your car's serpentine belt can eventually wear out. When that happens, you'll want to replace the belt right away to avoid a breakdown and additional repairs. Expect to pay somewhere between $150 and $250 if you want a professional to replace your serpentine belt.

Can a tight belt cause AC compressor to stop working?

A worn-out drive belt can put extra strain on the AC compressor, leading to compressor failure. If the drive belt is too tight, it can strain the compressor, and if the belt is too loose, it can slip off completely.

How much does it cost to replace a car AC belt?

AC BELT REPLACEMENT PRICING

The average cost to replace your AC belt is $58 - $126.

What happens if you don't replace a serpentine belt?

When the belt slips or breaks, your car's functions, such as the alternator and power steering pump, will likely stop working. A failing belt may also damage the parts it powers. Dealing with a broken belt or hose is bad enough, but if your engine becomes damaged, it's even worse.

What happens to a car when the serpentine belt breaks?

If your serpentine belt breaks, all of these systems will shut down and your vehicle will overheat. An unfamiliar noise or screech from the engine compartment is just one indication that your belt could be frayed, split, or worn out.

Does AutoZone sell serpentine belts?

A serpentine belt replacement is an essential part of routine auto maintenance, but it doesn't have to be difficult. Get the parts you need from AutoZone.

Will a loose belt cause AC not to work?

Power Steering and AC Not Working

If the serpentine belt is not functioning properly, it can prevent the power steering pump and air conditioning compressor from operating.

What is the difference between a fan belt and a serpentine belt?

A serpentine belt, also known as a fan belt, is a crucial operational component of many modern internal combustion engines. It's a single, long belt that wraps around pulleys in the engine, connecting and driving multiple engine accessories, allowing them to function correctly.

What belt controls the AC?

The serpentine belt is a long rubber belt that transports power to the engine accessories—the alternator, power steering pump, air conditioning compressor and (sometimes) the water pump. Sometimes the serpentine belt is called a drive belt, fan belt or accessory belt.

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