1998 dodge Dakota. The blower works on all speeds when it wants to. when it is working, if I turn the vent selector to off and back on the blower doesn't kick back on sometimes. while im driving it will sometime kick on all of the sudden.

The selection door, is operated by 1/4" vacuum hoses. When turning the knob or sliding a lever, to select between floor, vents, or dash deck for windshield defrost, vacuum is created by the valve body and the blower will then blow thru the desired vents. When these hoses/lines are compromised, especially on a vehicle over 15 years old it seems likely, vacuum won't be created, and the last working position, is normally where it stays! Until the lines are replaced.
Good luck.

Here's a video on your door that is not opening to let air out.

The vent selector works on vacuum. Those hoses are vacuum lines. They would connect to the back of the vent select switch, the one that you use to select what vent you want the heat to blow out of.

Change the thermostat, if it is more than 5 years old

Need 3 blower speeds or Blower Resister is rusted away

The blower resistor will burn and smell without blowing a fuse

Need to check the blend door.

Sounds like a blower motor problem. Check for obstructions around the squirrel cage, or a broken cage.

I would suggest changing the control head. You should be able to source a used unit from a local salvage yard.

I have an 2002 Dakota , my blower is on passenger side of truck, under dash by feet there was 4 small screws to take out blower just came out on mine. Something to check see if there is a electronic card in behind the blower, mine had that, change the card if it has one that controls your blower speeds, when mine went bad only had off and high for a few months, then none, changed blower no go, then found out about this card, dealer cost about $75 canadian, auto wreckers $25 canadian ... hope this helps.

replace blower relay