Am getting 3 codes, one says neutral safety switch issue, one says VSS issue, other that is really annoying says gauge cluster not communicating with ecm. What do I do to repair that? I don't even know where to start diagnosing this problem..
any help would be wonderful.

 

Pick a code, and start troubleshooting. Probably three separate problems there, but, it equally possible that one problem is contributing to one or more of the others. Start with the neutral safety switch.

 

I bought new VSS n NSS to start those code from a point of "new" as their inexpensive n 20 yrs old now. It's just the cluster not communicating with computer that has me insane. Though maybe a bad ground b/c the gauges worked intermittently except for the speedo which never worked since I bought the truck. Everything else from the 5.9L to the front/rear a/c works well so Im keeping the truck

 

Time to chase the wiring. Any sensor on the 5 volt bus can cause the No Bus problem..... Rear O2 sensors are one of the more common culprits. You can just unplug them, and see if the problem goes away. (but, likely will set some other codes.....)

 

Willing to try anything at this point. Though judging by the nightmare previous owners have created under the dash, I'm surprised anything is working.