Why does A/C only work on high?

sounds like you got hit by a stone, if the AC is affected, it possibly broke something related or shorted / broke an electrical connection. check fuses / damage

Year/make/model??? Are you referring to the AC fan speed only working on high inside the vehicle? If the fan is only operating on the high speed, suspect a fan motor resistor problem. The resistor may have to be relaced

replace the heater fuse/breaker and, the whole resistor set (each resistor controls a different speed on the heater fan: low,medium, high speed

Check the fluid, with the motor in park.

Its not a motor, its an Idle Air Control valve.

Depends, do you have 4 wheel drive? If so you can just use 4 wheel high, or if things get really slippery, use 4 wheel low and go slow, both in the drive position on the transmission shifter.

If 2wd, just use drive and go slow, again, if it gets slippery out, you can shift down in gears to go slower and to keep your speed slow.

If you're talking about snow and ice on just streets, then stick with 4 wheel high with 4x4, or "drive" in 2wd. You typically don't want to switch to 3,2, or 1st gear at highway speeds.

If you're playing in the snow, just use 4x4 high until you get stuck, then switch to 4 low to get out.

The only time I switch gears with the transmission (from drive to 3,2, or 1) is when I want to go really slow and keep it there. However, when I "play" in the snow, it's Drive only.

Does this answer your question? If not, let me know! Thanks

Sounds like you broke the linkage. I'd get down there, and manually put it in 2WD by you activating the linkage from where it's snapped, it's a bad idea to drive anywhere but on the mud if 4wd, if the axles turn at different speeds, it could snap a driveshaft, or worse, the differential.

the hood may be touching something to short it out

Go to your local shucks or auto zone and they can check any codes behind your check engine light and it's free. It sounds like one of two things a O2 sensor or your mass airflow sensor but they will tell you for sure

check the fuse