1999 Chrysler Town and Country lots of problems with '99 ch

'99 Chrysler T&C with 150k miles has lots of problems and I am trying to figure out if they are all related. First thing that started happening was the turn signal. It would work sometimes, other times I got nothing. Then the a/c light started blinking and hasnt stopped. Then when I put the heat on it only comes out of the drivers side and back vents but not the passenger side. Then the passenger window will go down but wont go up with the passenger button door, only with the button on the drivers side door. If that wasnt enough when I was driving up an on ramp the check engine light came on and the van wouldnt shift out of 3rd gear. Therefore it started redlining at 35 mph. I stopped the car and it seemed to reset itself once I restarted it but the check engine light didnt immediately go off. It has been doing this now everytime I accelerate too quickly or have to change speeds going up or down a hill. On top of all that now the van wont start properly. If I get in it will start for like 2 seconds and then it will die, if I try to start it again I get nothing and after the 4th or 5th attempt I dont even get a noise. I had someone tell me that the antitheft device is what makes it lock you out after the 4th time but that doesnt explain why it wont start in the first place. I have checked battery, starter, battery cables and they all fine. Does anyone have any idea what is going on? I could really use some help. Thanks!