Been having electronic devices in the truck getting weird on me, for the past couple of weeks. We lost a brand new GPS unit and a TPMS monitor. The idiot gauge in the instrument cluster showed great voltage. The gauge is, however, a real idiot!
I put the VOM on a hot source and it was showing 11.07v at idle. It did not change, with more engine RPM. I took the alternator out and got it tested. The AZ tester ran three different tests and all three came up with FAIL
in big red bars... When I pulled up the trouble screen, it showed a whopping 8.67v output under load!
I picked up a new alternator and put it in... When I first checked the voltage at the battery, it showed 11.01v..
I then realized that the batteries in the truck were probably pretty drained. After a short time, I was getting 13.1v at the battery.
I put the battery charger on and will leave it to charge overnight. It took two burned up electronic devices, for me to check into the problem. Other than those two things, everything else was working properly. I'm glad I caught it soon enough and before we left for Buttonwood!