Climate control blower running

V8 four wheel drive automatic 62,000 miles.

I went out to get in my truck and the battery was drained. I did not drive the truck for two days. I jump started the truck and while letting the battery charge the blower started running when the rotary switch was off. I ran the truck around the block to charge the battery a bit. I turned off the truck and the blower stopped. I restarted the truck waited a couple minutes and the blower came on again. When I turned the truck off this time the blower continued to run, key out of the ignition also. I tried pulling the 40 amp long fuse out but was not able to get it out, so I disconnected the negative lug on the battery. About two months ago the service airbag light came on, been on since. What is happening with my truck? Thanks.