I need a little help trying to troublshoot my A/C system on a 94 full size blazer. The A/C system was working intermittently before it died, compressor stopped cycling. I took it to a dealer who said the high and low pressure switches were bad, so I changed them out....no joy. I took it to Firestone who said I had an electrical problem that they could not fix so I took it to an electric shop that pointed out the only way to get the clutch to engage is to bypass both the low and high pressure switches and then tap the clutch. The pressure was low so I charged it back up and I got the clutch to cycle by bypassing the high pressure switch, but it does not blow cold air at all. Is it time to change out the compressor?