03 1 ton dually 6 speed from hell
 

So here's the scoop, bosses truck for pulling our equipment, crew cab dually diesel 6 speed 03 3500, it all started with the fuel gauge, it would randomly drop to empty and go back to normal, no big shake just keep an eye on mileage till I look further during down time, he went ahead and changed out the in tank sending unit with pump thinking that was the glitch, a week went by and everything was on the up and up.. till ding gauge reads empty.... wtf, so after digging around and not finding broken wires to the tank and checking the grounds I can see we say till down time, that's where the fun starts, well if the cluster didn't get the bright idea to go ahead and copy the fuel gauge, all the gauges now drop to the pins when ever it feels like it, the red security light stays lit and every once and a while she just decides she likes the location and shuts off and some of those times says piss off I don't want to run till I feel like running.... lots of fun with a trailer with a skid steer and other equipment in tow, check engine light isn't lit full time, and no bus flashes where the odometer is, pulled random codes that didn't lead me to a solution, took it to a diesel shop in the city to see if they could shed some light, after running tests checking wires and connectors they say it leads to the ecm being the issue, just great... put a new ecm into it..... nothing same crap take it out and luckily get most of the money back, someone talked him Into looking at the actual cluster as the culprit so he got a used one and I put it in and...... same crap, "known" things that cause these symptoms have shown to not be the issue and I'm at a loss, hoping some of you might have dealt with this in the past and might be able to show me the light at the end of this tunnel....

Thanks.