Automotive Air Conditioning Information Forum (Archives)

mhfd112 on Tue July 23, 2013 2:01 PM

Year: 2009
Make: NewHolland
Model: B95B

Air wasn't working well on this backhoe last year. Refrigerant was added by the operator. Said the air quit completely shortly after refrigerant was added. When I looked at it today there wasn't any power at the compressor. I applied 12 volts to the compressor and it ran. High side was 225 and low was 30.

Found three AC fuses. All checked good.

Any suggestions?

torque395 on Tue July 23, 2013 3:27 PM

Probably the low pressure switch is keeping the compressor from coming on. This is usually due to the refrigerant being low. It may have leaked it out almost as fast as the said operator added it. Even if it has some in it, and it probably does, Its not enough to turn the compressor on. Its odd, but alot of times AC systems will retain X number of PSI of refrigerant, but add more than that to it, and it will leak out back to the said pressure.

-------------------------
1996 Chevy Suburban 2500 4x2 6.5L Turbo

mhfd112 on Tue July 23, 2013 3:55 PM

I checked the low pressure switch with a multi meter. There was continuity between the two terminals on the switch. If it is low on freon, switch should be open shouldn't it?

torque395 on Tue July 23, 2013 4:17 PM

Yes. Turn on the AC and see if you have power to either side of the connector that goes to the low pressure switch. I believe there should be power at one side of it with the AC on. If not the problem is probably in the wiring or the switch.

-------------------------
1996 Chevy Suburban 2500 4x2 6.5L Turbo