Just an update about my dead camera ...

Although I nearly followed Fuddy's example and replace the camera I decided to remove the clarion camera (Fuddy's instructions were most useful in removing the camera) and sent it off to Clarion UK. After the very long cold winter I wasn't sure if the camera (CC-9301) or the Power box (CA-188) or inter-cabling were faulty.

Well it appears that it was the camera at fault. Clarion UK (in Swindon) confirmed it was the power regular that had blown and fortunately they would be able to replace it with a regulator from similar heavy duty camera (as the VX camera was a special for Isuzu a direct replacement is not available). The cost of mending the unit is £44.00 and would carry a 6 month guarantee, so hopefully I'll get a working camera back in the next few days and once reinstalled I'll once again have a working original camera (and fingers crossed it isn't the power box as well). But not bad for 44 quid for the investigating, the repair and the postage. A very friendly, helpful team down there as well - great customer care.