91 Eclipse automatic trans

Please help. I just replaced my automatic transmission. I got one from e-bay (I know don't say it) I was told it only had 80,000 miles on it but who knows. Anyway put it in last sunday. The trans oil looked ok. I pulled the pan and no gunk in there. I changed the filter, new oil new converter etc. I took it for a drive but only made it about 1/2 mile. The whole thing went out no noise just no go. I got it home and checked to see if oil was being pumped. I took of the hoses to the oil cooler and no oil pressure at all. Any ideas??? Is there an electrical connection that goes to the trans for the internal pump or ???? I am at the end of what I know to do. I just don't think the tranny is bad as if shifted fine and then nothing. I really could use some help on this one. Thanks to you all. Joe