I have a 2000 dakota sport that I just bought and went to go get it smoged for registration and evey place iv been to it won't connect. Took it to my regular mechanic and checked every fuse both under the hood and in the dash and there all fine. Any thoughts? I also would like to mention that the stero is not factor and that this truck was sitting for 4 years. Before even turning the engine over, I had it towed to my mechanic to replace all fluids and dropped the tank to be cleaned out with seals replaced.

 

Have you checked the wiring to the plug? Sitting for 4 years, maybe some mice got in there and chewed up the wiring.

 

That's what we're looking for now, will get back if nothing shows up.

 

I had the same issue with my '97 Sport.

One of the many wires in the diagnostic port actually supplies the power to the scan tool. Turn on the ignition switch to supply some power and use a tester to figure out which wire is hot against a ground. Then make sure the power is coming to the front of the diagnostic port. Mine wasn't. All I had to do was push the wire from the back to get it in contact with the front side and it worked fine.

On my Dak, the diagnostic port is easily unclipped from beneath the dashboard. The hot terminal was on the far right as you face the port, but I don't recall what color the wire was. But I think it may have been pink.