Thursday, September 4, 2014
Got the truck back today
All the main switches in the steering column have been replaced. It's very much a 'shotgun' approach, trying to replace everything that might be behind the earlier problems, but as the dealer said, the only alternative was to go even more extreme and replace the entire cab wiring harness. No problems surfaced on the short drive back from the service facility. We'll see over the next few days whether or not this approach has worked.
Thanks again to everyone who offered advice. I'll report back next week on whether it was the right advice!