Well...here's another issue I'm not sure is a real problem or just my imagination due to all of the problems I've had since some simple maintenance. The other day, I noticed my truck was turning over slower than normal. Since the weather's getting colder, I figured it was related to that and the fact the batteries are about 6 years old. Then my driver side headlamp burned out (low beam). I looked at a few Youtube videos on ways to change the bulb. While looking at the pieces and parts that needed to be removed, I noticed my second/driver side battery wasn't even hooked up (I have the diesel so there are two batteries). Hence the slower than normal turnover in the cold weather. So I've been driving around like this for about two weeks, ever since I had my truck inspected for possible coolant leaks. They found no leaks but must have unhooked the batteries to perform the work and forgot to hookup the second battery. Now I'm noticing a higher than normal charge rate on my gauge. I put a volt meter on the battery and it measured 15.1 volts. That's not excessive...I don't think...but seems higher than I would have expected. Does anyone think I've got a voltage regulator issue now or is this typical if one of two batteries in parallel has a low charge? Thanks in advance!