Thanks @LeonL - I uninstalled my Zero Off last night and checked every pin etc - the harness looked fine - I also had a spare main harness so I swapped that over - it had exactly the same issue. I'm really starting to think it must be a faulty puck - I've tried to email ZO but I haven't got a response which is annoying - I've tried a different email address so I hope i get a response. I'm in Australia so its a long way to send a puck back for them to test it. I'm hoping i can send them some photo's or videos to prove I tested everything and they can send me a new puck under warranty.