ve just purchased a 55plate Fiat Ducato Coral 680 SL motorhome with 24k mileage on, my question if anybody vcan help.I need to find out the type of immobiliser/alarm factory fitted make that is on this model as I would like to put a Thatcham Cat 1 on, however, if there is a cat 2 alarm on I just need an upgrade and that will save me a few pennies. Thanks in advance.

My guess is that the base vehicle had a Thatcham 2 immobiliser at manufacture and your require a 2-1 alarm upgrade.

A company with a great reputation for MH alarm fitting is vanbitz in Taunton. I am sure they can advise you.
http://www.vanbitz.com/