Take it to a small ac shop in town, they will check the charge on it for you.. Alternately go buy a ac charge kit and check the charge yourself.
If the AC gets cooler the faster you go, then it could be the compressor going (probably the flywheel)... You could be a little short of oil in the system too.
Note overcharging your AC could cause a rupture, so do not add r134a unless you know the pressure (buy a can with a pressure gauge).
If the AC gets cooler the faster you go, then it could be the compressor going (probably the flywheel)... You could be a little short of oil in the system too.
Note overcharging your AC could cause a rupture, so do not add r134a unless you know the pressure (buy a can with a pressure gauge).