2000 Ram 3500 No start, no bus

Working on a 2000 Dodge Ram 3500 with a 5.9, the vehicle came in for a no start. To complicate matters the vehicle also has a no bus message on the dash which the customer informed me has been like that for several years... In an attempt to resolve the no bus message and allow scan tool communication I unplugged every related module one at a time to see if the message would go away, every module but the instrument cluster leading me to believe that the problem may be the cluster itself. Any other suggestions along those lines would be appreciated. As far as the no start, having little to go on due to the lack of communication with the pcm I was able to determine that my 5 volt references at all of my critical sensors (tps, map, cam, crank, trans) are all reading 2.2 volts which lead me to think it was a pcm issue but after replacing the pcm the results remain exactly the same. Any insights into either issue would be greatly appreciated.

Cluster sounds like a likely culprit regarding the no bus. Can always try plugging a junk yard cluster in before buying a new one to confirm. Only takes like 2 minutes to pull anyways.

As for the no start, what's it doing? Diesel or gas?

5.9 gas, it cranks but with only 2.2 reference voltage at the sensors there is little chance that it's receiving any signals, thus it has no spark or injector pulse.. since I am unable to check anything with a scan tool I'm not sure where to begin looking...