I am getting ready to buy both a new dash and a/c parts for my non a/c '85 Pick-up.  So what all problems will I run into trying to do this?  What will need to be done to easily put a/c in my truck?  I live in Las Vegas where in the summer it can get up to 120 degrees and I NEED a/c.

I really have no clue, I have never done it.  However if I had all the parts that you do I would go for it! If you get EVERYTHING than it shouldn't be tough.  I know that you have to drill through the firewall in two points, but doesn't look too hard.  For a switch I would just wire one in, all it does is turn the a/c compressor on/off, your heater fan does the rest.  Just make sure to turn it off when you are done with the a/c other wise you are just burring $$$

PZ