I have a 2000 v6 mustang, my ac is blowing warm air, so i checked my low side pressure, it checked out at 50 psi. When I have the ac going on high the compressor clutch comes on for a second thn shuts off for four seconds then turns on again for a second, does the clutch havta run the whole time for the ac to work?

 

nope the clutch doesnt need to be on the whole time. it should be running for more than a second though before it stops

 

your system is low on refrigerant, it need to be recovered and recharged. i have a chart that tells you compressor on time based on ambient air temp somewhere, but 1 sec. of compressor on time is way too little.

 

^ thats what i was thinking but wasnt 100% sure.