is there a fuse in 1995 astro van for heater?

If it is blowing cold air it ain't the fuse is it....simple.
This is only a guess.
The old sytem of controling heat was cable operated valve. This system was replaced by electronic valves on some vehicles, may be also yours and needs the valve replacing. Check with garage if it does have a seperate fuse for the Electronic valve, but I would say both fan and electronic valve [if it has one] work from same fuse.

BB
March 2011