Hello Again,
I have tested the 3 booster relays in cab roof and all OK. I have also traced all the wiring in cab roof as per the wiring diagrams supplied and it seems OK. The problem I am having is that Fuse No. 10 in attached diagram keeps blowing when fans are switched on. When the fans or the ignition are not on I am getting 12V across the two terminals at fuse 10.
Tried disconnecting all relays but still get 12V across No.10 fuse pins. Don't know where the power is feeding from!