Volvo Penta 5.0FL PMDA Burning ingnition coils

[Michigan Jason]

I have a 5.0FL PMDA engine, 94 and had a no spark issue last week. I put a new MSD blaster 2 ignition coil in her and she fired right up. Ran really well on lake st clair for a whole day. At this time I didn't have my new radio installed so every time we stopped to fish, I would turn the key off completely and take it out. No problems all day. Now Saturday we took it out on lake erie and out to sugar island for the day before heading to elizabeth park for a country music concert. This time I had my new radio installed and naturally when beached we left the key in the run position so the radio had power. After a couple hours when we were ready to head out, I tried to start her up and she wouldn't fire up. Opened the engine bay and saw the ignition coil literally boiling with liquid oozing out of it and melted slightly from the heat. It was hot to touch obviously and there was once again no spark. Had to get a tow in, came home the next day and put a brand new coil in, still no spark. What gives?

So as of now I have a new coil installed and still no spark.