Just finished replacing the evaporator and charged up with r134, started to test the system in min temp, max interior fan, windows closed etc. Condenser/aux fan comes ON as high side reaches 225 psi for about two minutes, then the aux fan begins to cycle OFF for 3-5secs then comes back on for 7-12 secs, meanwhile high side pressures gradually creep up to 285-295.
I disconnected the aux fan and ran it straight to 12v and it runs continuously so it must not be the fan. I checked the aux fan switch on the dryer and it shows 12v continuously, so it seems to be fine. The voltage at the pigtail lead that powers the aux fan .15v. Switched the aux fan relay (c) with another one, made no difference, so I am all out of ideas. This is also the "small" Bosch aux fan, and it only comes ON at one speed when it does.... "scream"