Hi can any body tell me how to fit a new auxcilary belt to my 2005 1.9 jtd Doblo the old one snapped.
I have taken the shield off underneath so can now see the pulleys I can probaly work out what way the belts goes on but cannot see how the tension is alterd.

One of the small pulleys is sprung loaded on a small swivel arm. You will have possibly two or three of these smaller pulleys.

To adjust / move the pulley place a RING spanner on the bolt head in the centre of the pulley and gently turn clockwise. The pulley should move in a small arc on the pivot arm.

If NONE of your pulleys are of the sprung loaded type then your engine may use a "stretch"/elasticated belt. I have only ever seen one of these used on a Fiat and that was on my Stilo Abarth.