9400 Eletrical problem

[regor007]

First off great forum. I found you on youtube Rawze and your videos have been invaluable. I've learned a lot from them. Thank you!
I have a similar problem as muchos189 prostar. Sorry if I should of just posted in that topic.

My 2005 9400 gauges also started going crazy but there was no rain. Happened on a nice sunny day just out of the blue. The speedo, tach, oil pressure, volts, and temp gauges all just suddenly pegged at the 6 o'clock position. Of course the engine light and temp light are now too. After checking the obvious possible problems in the battery box I continued on from NJ to FL since the truck was running fine. I took it to a shop in FL and they got a code for data link failure so they just replaced the gauge cluster circuit board. That didn't fix the problem. They said take it to the dealer because now they were getting no communication from the ECM. Again the truck was running fine so I took a load back to NY. It ran fine on the way home. When I got back in the truck Monday to go deliver it was dead. Totally dead. No lights inside. Nothing. I got out and checked connections etc. Found nothing. Got back in the truck and interior lights popped on and the truck started. Same thing happened again after dropping off the load.

I took the truck to the dealer thinking it could be the ECM since the other shop was getting no communication. They called today and said it's not the ECM and asked how far I want them to go because it could take them a week trying to find the wiring issue. Typical dealer! Obviously I don't want them to go any further at $120 an hour. This is a truck I planned to upgrade in November so shelling out big bucks to the dealer is not an option. I've checked all the grounds and wiring from the batteries to the ecm.Where should I go from there?