I am starting to think that the intake could be leaking when the engine is at high RPM thus losing vacuum to the 4wd solenoid. Still not sure why it doesn't do it when the hubs are engaged though. Could be able to hold the vacuum when they are engaged better than when they are not. It runs perfect and has a new upper plenum in it though. I may do a smoke test on it just to be sure. I don't think I am going to let it bother me too much since the benefits of the manual hubs far outweigh the aggravation of a blinking light.

LOL