I've got an S650 with AC that is not working. I'm getting 2 blinks on the HVAC controller - which is 'Clutch open or over current'. I check the pressure in the system and it's at zero. Would zero pressure cause the compressor not to turn on and then the controller sees this as an under amp condition? In other words, if I charge the system with freon, will this fix the 2 blink on the controller too?
Well, the answer is yes. with 0 pressure in the system, the pressure switch is open. this prevents current from going to the compressor clutch. the controller reads this as a 'clutch open' (less than 200ma draw). and you get 2 blinks on the controller LED. Charged the system, got a solid red light. Compressor kicked in and started getting cold air. filled used a UV dye 134a and I can see 1 leak. It's at the threads of the pressure switch on top of the receiver drier. Looks like a fairly easy fix.
Just a follow up on this (cause it seems like no one ever does). Tightened the pressure switch 1/8 of a turn more. System has been holding pressure since and AC is working great. Of course it's winter now and it's -5F, so it's not like I need the AC any more. Heat has always worked great, but with zero snow this year, I haven't had to plow yet.