Confirmed. I get a 0 ohm reading between the left and right binding posts on my AI-1 Dreadnought (both positive and negative). You don't have a cold solder joint on one of the binding posts (or both) do you Fred? If you do not, it it is most likely a miswiring of the transformer primaries and secondaries. Very very low chance of occurance but not impossible of course. I would check you solder joints first though; especially since you said everything was working correctly when you first started using the AI-1.