starter turns off car but not on

[john]

On James' copper gst, he put it back together and took it for a pull. Noticed he had a boost leak and drove home and parked it. Did a boost leak test a few days later and tried starting the car but it wouldn't crank. It seemed it may be lacking power. I set the battery on the charger and it tested good. He put it back in the car and let it sit. Yesterday I went to look at it and the cables had some corrosion on them. I pulled the battery and there was some acid stain on the batt tray. I checked the battery and it was now down on fluid. I grabbed my battery and threw it in. The car will not crank still.

I checked the started wires and they seemed fine. I pulled the starter. I jumped it and it turned (through the stock wiring). It seemed to lack a little power so James brought it in to get checked. It tested fine. I hooked it up to the car and it worked again through the stock wiring. I threw it back in and all I hear is clicking. I thought I would rule out the battery by jumping the car and it would still only click.

Any idea why it won't crank? Why would the terminals start to corrode? A constant drain on the system? I will try turning the engine over by hand later. It has oil and was fine when it was shut off so I don't think that is the problem. Thanks in advance, John.