So today I do a valve check and oil change on an LT for a co-worker who lives a block away. Afterwards I hop on my LT to get a new cobalt drill bit at the hardware store for another project. I notice the speedometer is intermittent and the cruise control won't hold constant, it keeps shutting down. No problem. I know to splice the speedometer input wire where it has rubbed through on the crimp fitting at the top of the rear brake line. No trip to the dealer. No trouble-shooting. Right to the problem. Thanks to everyone for sharing their wisdom here in the past.