Can someone please be able to advise me on how I find out which AUX belt to purchase for my Daihatsu Terios. There seems to be numerous different ones and my existing belt does not have a number on
If you can measure the belt circumference, you can order a new one with the same circumference. You can do this while the belt is on the car using a simple piece of string or rope. Wrap string around the belt routing, remove it, lay out out flat and measure it.
Then note whether you have a "V" belt or a ribbed belt (note number of ribs) to be sure you get an exact match. Finally, you can measure the width of the belt.
With all that information, you should be able to get close enough to reliably order a replacement. All belts stretch somewhat so there's always a slight margin for error if you don't get it exact.
Also, if you know which belt it is and the make and model of your car, you should be able to order off a website that has a database and cross reference for these things. That's how I get replacement belts for my 35 year old BMW.
Answers & Comments
If you can measure the belt circumference, you can order a new one with the same circumference. You can do this while the belt is on the car using a simple piece of string or rope. Wrap string around the belt routing, remove it, lay out out flat and measure it.
Then note whether you have a "V" belt or a ribbed belt (note number of ribs) to be sure you get an exact match. Finally, you can measure the width of the belt.
With all that information, you should be able to get close enough to reliably order a replacement. All belts stretch somewhat so there's always a slight margin for error if you don't get it exact.
Also, if you know which belt it is and the make and model of your car, you should be able to order off a website that has a database and cross reference for these things. That's how I get replacement belts for my 35 year old BMW.