I need help with a diagram of serpentine belt for 2003 chevrolet trail blazer

There should be a diagram sticker on the hood or the fan shroud.
You can also draw a diagram before you remove the old belt.
There is a spring loaded tensioner you move over to release pressure on the belt.
I can upload a diagram if you can't find the sticker.

You use a breaker bar to move the tensioner, remove the belt and use the tensioner to put it back. You draw the belt and pulleys on a sheet of paper before removing, otherwise there should be a small diagram of the belt and pulley positions on the fan shroud or 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

You can get serpentine belt routings from Dayco website:
http://www.accessdayco.com/automotive#
It can be a little tough to find, but they are in there.
If you have A/C, yours should look like this:

It will have a diagram right above the fan blades to show you how it needs to be ran. Just need to release some pressure off the belt tensioner to make it all fit

CLICK on the following LINK. It should have the Belt Diagram you will need.
If you would: Before Clicking: Let me know if this helped you, or if you have any additional information or questions. Feel Free to contact me at FixYa.com!

http://www.2carpros.com/car_repair_information/year/2003/make/chevrolet/model/blazer/2003_chevrolet_blazer_drive_belt_routing_diagram.htm

PCM says there is a problem, whether you notice it or not. GET IT SCANNED.

My sincere apologies for the delayed response.
I am personally going back to answer your unanswered questions.
I have only been a free contributor to this site for the past 4-months.

I do not know if you still need this information, but I am going ahead and answering it anyway. You may want to Print the Diagrams for future use.

CLICK on the following LINK. It has the Belt Diagrams you will need.

If you would: Before Clicking: Let me know if this helped you, or if you have any additional information or questions. Feel Free to contact me at FixYa.com!

http://www.2carpros.com/car_repair_information/year/2003/make/chevrolet/model/blazer/2003_chevrolet_blazer_drive_belt_routing_diagram.htm

send an email to [email protected] and I will send the diagram to you

With a serpentine belt, there is a tensioner pulley, so use a socket on a breaker arm placed on the bolt of the tensioner. Turn it until the belt goes slack. It helps to get someone else to hold that in place while you remove the alternator.

Both serpentine and V-belt are described here, and there are diagrams :
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528003d76c