Thanks for the thread bump. I just got the issue resolved, so here’s the summary:
Despite my best efforts, I couldn’t get the display to work with the original APIM. I sent the APIM back (to Mitral @ AllThingsSync). When he tested it, he said he was getting memory errors with both IDS and FORScan. He also said that he took the APIM to Ford, and they were able to get a little further to where the memory was being read and they were trying to format it. However, in the end, they were unsuccesful in bringing it back to life.
He sent a different APIM out for me to try. After reconnecting everything, I still had a blank screen. I then decided to disconnect/reconnect all of the connections to the wiring harness. Surprisingly, everything now works correctly! I suspect that I didn’t have a good connection to the T-connector that goes to the ACM (below the display/APIM). When I was redoing the connections, I thought it was making good contact, but it kept separating. I found that I really had to press the 2 connectors together very tightly in order for them to stay connected.
I think the first APIM got messed up because I was using Syn3Updater (to update the Sync3 and NAV versions), but the engine wasn’t on and I didn’t have the battery on a charger. Lesson learned!
Thanks again to F150Chief and bill32399 for your help.