AC/Battery issues with 2003 Ranger

[2003 Ranger]

A few weeks ago I came out to find my battery in my 2oo3 ranger 4 Cyl. completly drained dead. The day before I noticed that the air conditioning lines were freezing up, I did not connect the two at the time. After recharging the battery I trouble shot the battery, cab and chassis wiring and found nothing. I began to realize that the AC compressor was running constantly and not cycling on and off with the engine running. I disconnected the wiring plug to the compressor and let the truck sit for two days and it started immediatly with a full charge. I re-connected the plug into the compressor and within 24 hours the battery was completely drained. I used a multimeter to find that there is 12 volts going to the compressor with the ignition switch off. The AC continues to freeze up after about 30 miles. I checked the refrigerent and it is in the normal range. I don't have a factory manual only the Haynes and it is not much help with troubleshooting the AC wiring. Any suggestions?
My temporary solution was to disconnect the battery using a heavy marine switch cut into the battery cable. It is getting old raising the hood every time I use the truck.
Tony