I just bought a 03 Dakota 4.7L 4X4 SLT that had a oil pressure problem. I rebuilt the engine on my 98 dakota 2.5L and was a motorcycle mechanic for 8 years so I know how to turn a wrench, but I am not sure what to do about this one. Cold it has no problem but when the truck warms up and only at idle the oil gauge drops to 0. While driving warm the gauge reads about half way to a little past half way. Why they did not put in psi level lines on the gauge is beyond me. I put a new oil pressure sender unit on it new 5W30 full synthetic oil and new filter, still had the same problem. There is no ticking or knocking while idling warm for five minutes with the gauge on 0. So I went and got a mechanical gauge installed it and it shows about 4-5 psi at idle when warm. I would just mount the mechanical gauge and call it good but the check gauge light and dinging drives me crazy. So my question is what are some possible fixes for the original gauge? I will start tracking down and checking all grounds. Also I will be checking connections and continuity in sender wire. Anything else someone has had a problem with or anything else it could be? Or am I better off disabling the check gauge light and dinging, if so how?