B-alto made a post on my post ‘Prevent Power issues”, He brings up a good point I might have not stated clearly.

In the concept of “preventative maintenance” this is not some thing to get into just before a job, I am thinking about rain out days, days with no jobs, or time when if you have the “Snap Oops!” its not a big panic to correct.

Thus the term is “Preventative” not “destructive” Maintenance, but if you do find some thing like B-alto did he saved himself a huge issue down the line by looking for issues, so don’t be afraid to look but use understanding as to when, I do live by the old adage, Just before a job or on a job If it’s working DON’T MESS WITH IT.

B-alto way to go finding an issue, Pray tell what was the symptom or problem that had you looking at the connection, did you have a power drop problem or just checking all the connections?

Thinking back, it was that the electronic malfunction light would come on when I was down the road a few miles. I noticed the hot wire was corroded as stated. There is a very fragile lobe on Mack alternators and its hard to get a back wrench behind it if at all possible. I ended up replacing the alternator, no it didn't solve the EM problem but like you said a good battery and alternator is a must. It was getting old any way. The E light still comes on sometimes and the code reads 3-4 injectors are bad. Mack said that couldn't be, they said the harness is probably dirty? Its hard to work on now in a snow bank but this spring I'll address it.

Trouble never happens when the weather is nice.  Working on stuff  in a snowbank sounds familiar.  Alternators are expensive too.  Replaced on both trucks after nine years.

 Tell me about it Tele. This year for myself and another operator it was batteries on the first really cold day. They were cranking the trucks up without a blip till that day then the next it was the screw you Im done working. On my rig the batteries were 7 years old so I guess we got our moneys worth out of them.

There's a guy in Bemidji, MN Terry's electric, that will rebuild an alternator for cheap like $50. This one he couldn't get the bearing off. He said one in a thousand get stuck. He does stock rebuilts though I think it was around $180 which is not bad. I'm not sure what Mack would want but I bet it is high. Terry's good, he'll rebuild while you wait. I bet you could even have one shipped.