2012 VNL D16 I'm getting battery voltage at the relay with the engine off. When I engage the preheater before starting the truck, it gives me error #1 and #2. When I start the truck, it works normally without error codes. Does this mean that my problem is in one of the cables from the alternator to starter to batteries? I would think I should have other symptoms, like the alternator not charging the batteries or starter issues, but everything else seems normal. I've replaced the batteries, the preheater element, and the relay.
