Hi guys looking for some help with a crown wav.the machine will not start up. no dash display on bdi when i turn the key switch i get power to the controller plug in the curtis hand unit and checked fault it shows "can fault" checked fuses and connections all look ok.the drive tow switch works ok so when i press it the brakes release and machine can be pushed. battries are ok 25.4 volts.line contact is getting no negative feed from the controller any ideas ?