Okay, so it's probably the same one as mine, the original digital varistream.
Here are the installation instructions, as you can see, the pressure switch isn't wired in at all.
http://tinyurl.com/bsuvn8qIn the 5 years I've used my 100PSI Shurflo (pretty sure it's the 8000-946-138) I've never had a problem with the actual Varistream or pump, the only time I had issues is when I originally set up the system using scotch-lok crimp connectors, they fail miserably over time, resulting in all sorts of problems. Best to use normal crimp connector (bullet or blade)
If you've got any of them in your system, do away with them as well.