1st Gen FTW - It's AutoMedic!
Join Date: Jun 2008
Location: Garrison, ND
Your low pressure reading should be while running.
Sounds like you might have a low pressure situation actually, as though you might have suddenly dumped some pressure due to a bad compressor seal or something. Double check all your connectors under the hood, including bulk connectors, and look for any wires that are exposed to lots of water or road debris, and check for damage.
I was going to suggest transducer, but you already checked that. Double check to make sure it is screwed in all the way, and the connector is seated well...
and DO keep us posted.