03 Isuzu Rodeo V6. I think I fixed a problem but now my AC button is like turbo!?

Little backstory. My temp gauge was intermittently dropping all the way to the Cold mark even though everything was at operating temp. I started carrying a Bluedriver around everywhere I went to try to capture some live data. The needle buried in the C on a drive one day, the data reported my coolant temp was coming in at 18 degrees! Next day (today), I replaced the coolant temp sensor. Hopefully that took care of the problem (like I said, it was intermittent). But now, as soon as I turn my AC on, my engine speed jumps to about 1500 rpm. It'll get up to 35 mph without even touching the gas pedal! The brakes don't like being in a parking lot or at a red light, so I turn the AC off and the tach drops back to about 700 which is normal. It wasn't doing this before the new temp sensor. WTF?