Additional info Your system with factory controls and strange fittings. You may have one of many aftermarket systems that are available for the S10 they use GM controls and may use either aftermarket parts or GM Harrison parts. There should be tags or paperwork or something to help figure it out. If I had it my shop I could tell immediately.
if you had pics and placed them in a yahoo breifcase for viewing would be helpful. pic of COMPRESSOR Condenser Drier or Accumulator Evaporator case. etc.
2-3 views of each.