91 Ford Escort LX +Battery terminal smoke

Hello people. My problem is this. My daughter has a 91 Ford Escort LX 1.9l . Before it completly died it was having trouble idleing when she came to a stop. Almost to the point where it dies. Then one day it just refused to start. I just took out the altenator and took it to Autozone so they could test it and it was fine. So I decided to buy a new battery. I hooked it up and the + terminal on the battery started to smoke. What in the world could be causing this? Any advice would be helpful. Thanks.

You may have the terminals switched. The cable may be grounded somewhere between the battery and the starter. Inside of starter may be grounding out. Check the fusible link to see if it is melted.