So I took my 07 Tahoe 5.3Lt to get it checked out for an ac issue. It blows air, just isn’t getting cold and when I turn the heat on, it seems to be blocked. Had a vacuum & recharge. Mechanic checked the compressor. It’s fine.Turns out the 10a fuse to the compressor isn’t getting power to kick on. I replaced the low pressure switch. Still nothing. Now my accumulator pipe is making a hissing noise. I’m no mechanic. Just want to know if I’m missing something small. I have a new compressor, condenser and accumulator ready to be installed. But the mechanic says it isn’t any of those. Might be a wiring issue. Any help on this?