I have a 1998 V70XC with a 100,300 miles on the odo and it runs good but I', having an issue with a/c system. It has a new a/c compressor,accumulator, a/c accumulator to compressor hose and new high pressure sensor. The a/c compressor has been charged and holds a charge but the clutch wont engage unless I jump it at the main relay pins located in engine bay fuse block. The only only way it will engage is if I erase those 2 trouble codes...that's correct, when I erase those 2 codes(P1308/P0107) the a/c clutch will engage briefly until CEL illuminates. The acceleration sensor and MAP/Barometric sensor. Both sensor plugs have 5v present. Is it as simple as replacing both sensor? I can't find any other reason for the a/c not receiving the command to engage the clutch. Any suggestions will be highly appreciated.
I left something out that I found, the 3pin plug that goes the high pressure sensor only has 1.2v instead of the 5v reference it's supposed to have and my front cigar lighter plug only has 3v instead of 12v. I found a wiring diagram of the climate control system and the cigar lighter plugs circuits look like there connected.

 

Well it's getting warm again and I'm still having same issue with my A/C system on my 1998 V70XC. The DTC's are P1308 and P0107; P1308-Acceleration sensor circuit low signal, P0107-Map/Barometric Pressure sensor. Both sensors have been replaced with brand new factory replacements. If I jump a/c compressor from engine fuse box at a/c relay pins the clutch engages, if I jump compressor from high pressure sensor plug the clutch will engage. I've swapped in a known working relay to no avail and a known working CCU and evaporator unit to no avail. The High pressure sensor plug doesn't 5V's present at the reference pin, it's only showing 1.2V. I've tried to trace it backwards to find out why it doesn't have 5V present with no luck. Does anyone have any suggestions of where to go from here, I'm stuck?