Hi Rog,

I would first ask you, 'What has changed'?

Then, 'Why do you think this unit is the cause'?

Have you had the battery load tested? Not just voltage but it's ability to hold a charge, to provide the necessary power under load conditions.

Try disconnecting the negative terminal overnight. If when you reconnect in the morning, it's dead, the cause is not a drain.

Get back with me
Mike