Dakota SXT 3.9L

• Manual transmission
• 86,435 miles

Back in February while grocery shopping I came back out to my truck and went to turn on the defroster to melt snow on the windshield and noticed I had no blower. I checked the fuses and nothing had tripped. When I got home I called several auto parts stores to ask if they knew of any problems concerning Dakotas with blower problems. I was told the resistor might have blown. I ordered a new one and replaced it. While doing the replacement I disconnected the battery as I was working near the passenger side airbag and didn't want it to inadvertently activate it. Once the I finished replacing the resistor I reconnected the battery. Several hours later I needed to use the 4wd and found I couldn't engage it because none of the lights that indicate what position the transfer case is in would come on and the switch which is electronic wouldn't shift the truck into 4wd. I haven't been able to find a reason why the switch would quit working after disconnecting the battery or how to repair this short of going to a repair shop. Does anyone know of a solution to this????
And to complicate this the blower now works intermittently or if left on will come on when it fells like it. It worked fine for two weeks then started with the problem. I have plenty of heat cause I can feel it coming up thru the defroster vent. The low setting never worked prior to the resistor blowing but works now. Again does anyone know of a solution to this and could this be tied to the 4wd switch problem???