I don't remember seeing this problem before on this forum. I posted last week in C5 General that I was having "starting" problems. I thought I could be draining the battery with Window Valet, Valentine detector plugged in and memory seats adjustments before starting the car thus draining the battery so much that it did not have enough juice to start. Well the responses I got indicated that it was not the problem and that the battery was probably dead or dying. So I took the C5 to the shop I take all my vehicles to. They tested the battery - Interstate Orbital - and said battery was good. They tested the alternator and said they was charging correctly. Then the tech noticed that the negative cable was loose and attempted to tighten it but said the bolt was bottoming before getting tight. Said noticed this problem with after market batteries before on GM cars/trucks with side posts. Spoke to the shop owner and asked if he could change the bolt or put in a washer since I did not want to return to the OEM battery. He said he did not like the OEM battery either. He said he could probably grind down the negative cable bolt a bit through trial and error to get it to tighten correctly but would need more time than his short Saturday hours. Told him I liked that solution better than getting a new AC Delco battery. What do you guys think? I can see were a loose cable will let me have enough juice for the Window Valet, the memory seats and/or interior lights etc. but not enough juice to pass through to the starter.

 

Grind or cut the bolt to shorten it.

You can always pickup new battery bolts at any parts store.

 

Hi, there have been numerous instances of the too long bolts causing batterys to be discarded before their time, and also of the too long bolts ruining the terminal by being overtightened and cracking the terminal, causing leaking, and even being overtightened to the point of going through the terminal to the inside of the battery causing leaking and corossion of the terminals.
The solutions are simple, go to the auto store and get a shorter replacement bolt, or put a copper washer or two in and tighten to 11 ft pds, if the cable can't be wiggled with heavy hand action it is tight . Don't know why your mechanic wants to make such a big production out of it . Also check the pos bolt to, if one is loose the other should be checked closely also.
Good Luck