Hello Scotty. I have a 1996 Mercury Sable. I went to put a battery in it and after I hooked it up, the radio, hvac and speedo didn't work. I found the 5A radio fuse under the dash and it was blown. I went to put a new 5A fuse in it and it sparked and blew immediately and left a burning smell in the interior. What could've happened? Everything worked fine before I installed the battery. Thank you in advance.

if you didn't put the battery terminals on backwards, you got a power surge hooking up the new one and that fried something in that fused circuit. You will have to test it all to find what shorted out using meters

Thanks so much for the reply, Scotty.

I didn't hook it up wrong. I did hook up the negative post before the positive if that means anything. When I go to put the 5A fuse in the radio slot with the power off, it sparks and blows the fuse immediately. Is that a short in the wire?

Could it possibly be another blown fuse under the hood causing this small fuse under the dash to blow?

FYI...This is the OE radio. It's that pod radio that is combined with the heat and A/C controls.

I just don't know where to start. Do you have a video that might help me troubleshoot this?

Thanks again!