Can anyone tell me what this is? View is looking aft into the engine bay just over the fuel filter. It was attached to the top of the lift pump bracket with a small plastic clip. It is a 2000 3500.

Thank you in advance.

 

I can't tell how far down it is but it might be the diagnostic connector. I have one around that area that my quadzilla plugs into, just a plug hanging there.

 

That would my guess as well.

 

You say it was attached. Can you take a picture further away with the sensor attached where you found it in the first place? Be easier to identify then.

 

If you look just to the left of the sensor/plug in the picture you can see where it was attached. There are three posts with nuts on them holding the lift pump onto its bracket. On that same bracket, next to the posts, there is a small rectangular black plastic fitting that the sensor/plug slides onto. Hopefully that all makes sense...

I had to remove the plastic fitting to put on an aftermarket fuel pump so now the sensor/plug is just dangling around back there, tucked into some other wire bundles.

 

I've also got a 'loose' sensor in that area. If your truck has had the fuel lift pump relocated to the tank it may be the old plug for that but I seem to remember seeing mine before that was done.

 

Diagnostic port for cummins use only. Cummins does use their 5.9 diesel for other applications other then Dodge trucks.

 

Yep, exactly. The thing plugged into the end of the connector is basically just a cap to keep the gunk out.

 

Thank you. The wealth of knowledge on this forum is incredible.