Belt Routing Diagram in a Car – Complete Guide for Proper Serpentine Belt Installation

A belt routing diagram is a crucial reference that shows how the serpentine belt or drive belt loops around various pulleys in your car’s engine. This diagram ensures the belt is installed correctly, keeping essential components like the alternator, power steering pump, air conditioning compressor, and water pump running smoothly.

Belt Installation DIY

What Is a Belt Routing Diagram?

A belt routing diagram is a visual guide printed under the hood or in your vehicle’s service manual. It shows the exact path and direction of the serpentine belt as it travels around multiple engine pulleys. This diagram helps you correctly reinstall the belt after replacement, preventing misalignment and engine performance issues.

Ensures Proper Belt Installation

Incorrect routing can lead to belt slippage, noise, or engine damage.

Prevents Component Failure

Correct alignment keeps the alternator, water pump, power steering, and AC compressor operating efficiently.

Saves Time During Repairs

A clear diagram simplifies serpentine belt replacement for DIY mechanics and professionals.

Improves Engine Performance

Proper belt tension and routing ensure smooth power delivery to all accessories.

How to Use a Belt Routing Diagram

Locate the Diagram: Look under the hood or near the radiator shroud. If not present, check the owner’s manual or vehicle service guide.
Compare Belt Path: Study the diagram and compare it with the actual pulley layout in your engine bay.
Install the Belt: Follow the routing path shown in the diagram, making sure the belt sits correctly on each pulley.
Check Tensioner Alignment: Use a belt tensioner tool to apply proper tension if required.
Double-Check Installation: Once installed, verify that the belt is aligned and fully seated before starting the engine.

Common Components in a Belt Routing Diagram

Crankshaft Pulley – Drives the entire belt system.
Alternator Pulley – Generates electrical power.
Power Steering Pump Pulley – Helps steering effort.
A/C Compressor Pulley – Powers the air conditioning system.
Water Pump Pulley – Circulates coolant through the engine.
Idler Pulley & Tensioner Pulley – Maintain proper belt tension and routing.

Pro Tip

If the original belt routing sticker is missing, take a photo before removing the old belt or look up your vehicle’s make, model, and engine size online for the correct diagram. Proper routing is essential for safe, reliable operation.