2 weeks ago my 2008 Dakota started having strange transmission issues. When the tranny is cold it shifts fine, but about 5 minutes into a drive it downshifts HARD into 3rd and stays there. The tranny was rebuilt almost a year ago, so I took it back to the shop and the owner hooked his fancy SnapOn diagnostic device to the truck and everything was pointing to an electrical problem. I know troubleshooting electrical issues can very easily lead down multiple rabbit holes and I just can't invest much money into this truck.
Anyone have similar issues with their Dakota?

 

Most likely a valve body problem.

 

How's the fluid level?