I have an old 1993 G20 van, recently I hit a slick spot and hit my brakes rather hard. This made me slide and I went through a large snow/ice drift with the passenger side tire. Shortly after I noticed the parking brake light is staying lit on the dash. I still have brakes, they seem not to have any slop in the pedal, but the light is worrying me. I've checked the actually parking brake pedal. It is old and rusty and I have to pull the release handle and lift the pedal by hand, but this doesn't do anything for the light.
What should I check?

Side note: My ABS light has been on for years and was told that it was a sensor or something. That wast years go and has never been an issue.

 

Drove the van again today. First thing I did was pump the brake pedal. This made the brake light on the dash go off. During the test drive I hit the brakes rather hard and the light came back on. I pumped the pedal again and the light goes off. Pedal seems a little soft at times and stiffer other times, if that makes any sense.
Any ideas?