Watch your charging system

A similar thing happened to me with a tech at the Fruita Pete dealership..
I had a starter replaced and he forgot to reconnect the ground from the starter to the frame..... Yeah.....technically when you bolt-on the new starter, it "is" grounded to the frame......but the ECM didn't think so.....and the the "Shut Down Engine" light kept on flashing whenever I started pulling a hard grade...Two weeks later, that starter failed...replaced it on warranty and Rush Peterbilt told me about the "loose" ground cable.

 

Back around 2001-2002, I was driving a MACK, I noticed my volt gauge was pegged! All the way to the right. Since I would be by a company 'faction' shop, I stopped in to let them take a look. I told the guy, that when I was on the interstate, it would peg. Well, this so called shop manager went to my truck, and while it was IDLING, checked the output. Since he got a normal reading, he said nothing was wrong with it.
I took it up with a mechanic, he had me floor it as he checked it. 17.9 volts! He went to his manager, who proclaimed that he checked it, and nothing was wrong with it, so nothing was going to be done with it.
The mechanic told me what to expect. Sure enough, the rotten egg smell.
When I couldn't get it started on a fuel island at a T/A, it all came to light. New alternator, and two new batteries. Not to mention a jump start, and electrical systems check.
Total bill: over $800!
Boy! Was my company ticked at that shop manager.

 

I wonder what can cause one of the old analogue volt meters to jump around a lot. Its a 2001 Freightliner with 50,000 miles on it. It runs fine and starts fine but when I start it the needle acts crazy and will drop down to nothing and back up. When it drops down I can peck on the front or on the dash and it will come up but may drop back down. After its warm I think it straightens up. It did it out in Bakersfield but I drove it in to Oklahoma and been driving it quite a bit. This sounds like a loose wire doesn't it. It had been sitting for several months when I picked it up, but they had just put a set of battery's on it.