My dakota will only blow air/heat on the right side of my truck. Also the speed will not work on either low or medium, but I have no problem with the temperature of the air.
Lets start with the air. You need to remove the knee bolster under the streeing wheel so you can see under the dash. It sounds like the left air tube has came loose just put it back on
and push firmly when you do. On the blower speeds you have resisters that controle low and med speeds. Log onto auto zone and look your truck up in the DIY repair pages. The A/C section will show you this stuff and how to replace them.
