blower fuse started a fire in my engine compartment!

[fz500sel]

I was driving down the road today in my '93 400E with my A/C on and my blower "hiccuped" for a second. About a minute later I was slowing down at a red light when I noticed smoke coming out from the drivers side of the hood. I immediately pulled into the turn lane with my flashers on and turned off the blower fan. I popped the hood and the blower fuse was completely gone and all of the plastic around it was on fire. I blew it out after a couple tries. The hood pad even melted. What should I do? I'm afraid to even try the A/C now.

This has got me worried because the '88 300E I sold to my neighbor had the same thing except the only thing the fuse melted was the plastic cover that goes over the fuse.