The low side pressure of the compressor goes into a vacuum and the high side reads 150 psi. Need to know what would be the cause of this problem. Filter drier or expansion valve(and where the location of it is) or if it's anything else would be the problem. Thank you.

 

if the low side is pulling a vacuum, there is a blockage in the system. probably the expansion valve. it's mounted to the evaporator which is behind the glove box. blockage could be in the any of the components, but the expansion valve should be replaced anyway if you have a blockage anywhere since contaminants are obviously flowing through your system. remove the evaporator by removing the glove box and disconnecting the lines at the firewall disconnect the drain tube also, then unbolt the box and pull it out. replace the expansion valve, and while the box is out, disconnect the other end of the hard lines and flush them with an ac system aerosol flush kit. comes in a can with a tube attached. This will clean the lines and make sure the blockage isn't there. you can probably use clean compressed air to see fif the condensor is clogged. make sure the other lines are cleaned as well and replace the recevier/drier LAST since the system needs to be sealed once the drier is installed or the drier will become saturated with ambient moisture and will not function properly once the system is charged up.