The fan belt of my 2004 Chevy Impala broke 7 wrapped behind the main pulley or what I believe to be called the serpentine.

With a non sc
one belt. If you have sc that show two belts.
The picture is non sc. If the new belt is too loose, maybe the tensioner has a problem or you got the wrong belt? Check the accessory pulleys/bearings, see if any movement, the wrong way.

If there is no diagram pasted in the engine compartment, check your owner's manual...or else go to your local auto store warehouse or Chevy dealership...usually the parts counter person can print out the diagram specifically to your vehicle. Since you did not mention the engine specs- I'm going to generically how to install a serpentine belt.

1.) make a loop and slip the loop around the crank shaft pulley
2.) continue looping the belt around the water pump pulley
3.) ...around the A/C pulley
4.) ...and around the idler pulley
Skip the alternator pulley for now- you want to do that one last.
5.) Continue placing the belt around the power steering pump pulley
6.) and over the belt tensioner pulley
7.) Now move the belt tensioner position so that you can loop the belt over the alternator.
8.) Now double check to make sure that the belt is properly and securely fastened around each pulley's grooves. Don't start the motor until you are absolutely sure... and can visually verify that the new belt is installed properly. And don't have anyone (or pets) standing around the car or open engine compartment when you initially start the car just in case the belt breaks...serious injuries can occur!
I've attached a generic drawing it may or may not fit the description of your auto.

Just cut it with a blade

Which engine do you have ?
There should be a diagram on the hood or the radiator support.

Pop the hood of the car and locate the serpentine belt routing diagram. The diagram on the 2003 Chevrolet Impala is on top of the fan shroud. The diagram will be a picture of all of the accessory pulleys and how the serpentine belt is routed among the pulleys. This diagram will give you the exact direction for routing the new belt onto the pulleys. If you cannot find a serpentine belt routing diagram, take a notepad and pen and draw out the exact routing diagram of the old belt across the pulleys.

2 Locate the serpentine belt tensioner. It is located below the alternator on the left front side of the engine. The tensioner on the 3.4 liter, 3.5 liter and the 3.9 liter engines will require a 3/8 ratchet to release the belt tensioner. The 3.8 liter engine will require a ratchet and a 15 mm socket for the belt tensioner. Rotate the belt tensioner clockwise to loosen and remove the belt from the belt tensioner pulley.

3 Slide the old belt from the belt tensioner pulley. Remove the belt from the remaining pulleys and pull the belt from the engine compartment.

4 Route the new belt across the crankshaft pulley first. The crankshaft pulley is the big pulley on the bottom of the engine in the center. Then route the serpentine belt across the remaining pulleys as directed by the serpentine belt routing diagram. Leave the belt tensioner pulley for last.

5 Rotate the belt tensioner clockwise again to relieve the tension and slide the new belt across the top of the belt tensioner pulley. Release the belt tensioner and the belt will tighten up as the tensioner applies pressure to the belt. Make sure the new belt is properly seated in all the pulleys.

6 Crank the engine and inspect the belt again to make sure that it stays seated in the pulleys.

Read more: How to Replace a Serpentine Belt on a 2003 Chevrolet Impala ' eHow.co.uk http://www.ehow.co.uk/how_6120665_replace-belt-2003-chevrolet-impala.html#ixzz1Yi6QLAjb

I don't know of any way to by-pass the A/C compressor or any component in a serpentine belt system; but, you can unplug the compressor clutch (at the nose of the compressor, behind the pulley), then the compressor will not turn and the pulley just acts as an idler.

The serpentine belt routing diagram on a 2000 VW Passat 1.9 TDI - 90 HP


CS = Crankshaft
F = Fan pulley
Gen = Alternator
T = Tensioner
AC = Air Conditioning
PAS = Power Assisted Steering
WP = Water Pump

GM use a particular item on one of the idlers
there will be a 1/2" square hole in the center of it
use a strong bar and lift the pulley up against a spring
install the new belt and when properly installed let the pulley back onto the belt

the serpentine belt is the only belt in this p/u truck,its breaks off in strips the length of the belt

Click on the following free direct Link. It has the Serpentine Belt Diagram and Tensioner location for your 2003 Chevy Impala.

http://www.2carpros.com/car_repair_information/year/2003/make/chevrolet/model/impala/2003_chevrolet_impala_drive_belt_routing_diagram.htm

GENERAL/Standard Rules to Removal the Serpentine Belt with a Tensioner:
A. Find the Tensioner(s). (See Diagrams on Link)
B. Using a Serpentine Belt Tensioner Tool, Or Wrench OR Ratchet, Rotate/Move the Tensioner USING THE AVAILABLE NUT (on the Pulley or Arm Base) OR the OPENING (3/8ths or 1/2 inch square opening) rotating the Tensioner Pulley/Arm - moving it away from contact with the belt and towards the area where the belt is not in contact with the Tensioner Pulley. The Tensioner is spring loaded, and is hard to rotate/move.
C. Remove the loosened belt off one of the other more easily accessed Pulleys.
D. DO NOT quickly release the Tensioner, but gently allow the Tensioner to rest in its closed position.

Standard Rules for Installing the Serpentine Belt with Tensioners:
a. Pick a Pulley that is most easily accessed. This will usually be on top. This will be the last Pulley that the belt will go on.
b. Using the Diagram: Install the new Serpentine Belt on the remainder of the Pulleys....over, under, left right.
c. Using a Serpentine Belt Tensioner Tool or Wrench or Ratchet Tool: Rotate/Move the Tensioner Pulley/Arm "away" from Belt contact area on the Tensioner. This spring is pretty hard and with a new belt, it will be even harder to install. Rotate/Move this to as-close to the maximum allowed inorder to have enough slack in the belt to get it up and over the last pulley.
d. Using your other hand - Pull the Belt up and over the Last remaining Pulley.
e. Before releasing the pressure on the Tensioner, visually inspect the remainder Pulleys and the Belts' Positioning on them.

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.Com!