I finally dug in and got my A/C going. S. VA is hot and humid so it's real nice to have it. My question is for anyone that has an LB or maybe a 555 or a B95 etc and has factory AC. Does your clutch stay engage basically all the time when you have the AC turned on? I'm going to try bypassing the relay to see if that might be bad, but in the mean time I wanted to see if I'm chasing nothing. The pressures are ~30 low and 195 high. Background: I bought the machine a while back and the AC wasn't working. The condenser and evap both had bottom rot from the PO's lack of cleaning. I replaced my condenser, evaporator, thermal expansion valve, the blower and finally the compressor when I couldn't get the system to take freon. I haven't replaced the low pressure switch. The clutch comes on when I press the AC button in the cab and it shuts off the same so I think the pressure switch is fine. It's been fun and pretty expensive, but at least she's blowing cold air now. I've learned a ton more than I ever knew about A/C systems so I'm pretty happy about that and figure the knowledge was bargain priced. ~$400 each for the condenser and evaporator. $60 for the TXV $50 for a new Spal blower and $200 for the compressor. The only thing I didn't figure out what it's function was a knob assembly like the fan speed knob, but it's mounted on the A/C blower housing down by the floor under the back right of the seat. Wiring harness appears to be factory. I'll post a couple of pics in a few minutes. I just wanted to get the question out there first. Thanks for any help. View attachment 20260418_091959.jpg View attachment 20260418_092003.jpg View attachment 20260418_092007.jpg View attachment 20260602_163727.jpg
I guess you just have to figure out the right way to ask google to get the answer lol I just tried again about the second rotary switch and this is the answer I got: - "In a backhoe's air conditioning system, the second rotary switch is the temperature control switch (or thermostat). While the primary rotary switch handles blower fan speeds (e.g., Low, Medium, High), the second switch regulates the cabin's cooling by cycling the A/C compressor clutch on and off to maintain your desired temperature." - "Second Rotary Switch: Controls the Temperature/Thermostat to set how cold the air is. It uses a capillary tube in the evaporator core to sense temperature and prevent the unit from freezing up."
Does the clutch stay engaged all the time A/C is on? That all depends on the type of system. If it is an expansion valve system, yes. If it is an orifice tube system, no. Variable displacement compressor, yes.
Thanks. Yes, I'm pretty sure it stays on the whole time the ac button is in the on position. I didn't think all txv systems stayed on.