Last year I had noticed some corrosion on my battery positive terminal and it looked as though the battery had leaked with the previous owner. I removed the battery and tray and gave the whole area a good washdown with a baking soda solution.

A couple of months ago, I started getting the IPC defaulting back to the odometer on startup and also the HUD switching to the display with oil pressure rather than fuel level (which I usually leave it on). I had noticed that this happens any time the battery is either disconnected or gets extremely low. The battery positive cable had started corroding again. Twice, I was almost stranded and had to manually twist the **** out of the terminal to get the car started.

I looked in my C5 parts catalog and found that the battery positive cable, part # 12157085, is listed, but the individual components (cable, bolt, rubber boot) also have their own part numbers. I emailed Gene at GMPartsHouse to ask if the cable part shown above included the bolt and rubber boot also. He wasn't sure. So I ordered the cable AND the bolt (had to buy a pack of 6) AND the rubber boot (about $70 worth of parts). When the box arrived, it turns out the cable assembly (part # shown above) already comes with a bolt and rubber boot. So if anyone else needs to replace their battery positive cable (which is a very common problem with C5s), you just need to order the cable.

My battery positive cable's bolt was so corroded that it had become one with the spade terminal on the end of the cable. I had to put baking soda on the terminal for about half an hour and use a pair of vise grips to break the bolt loose from the battery. I never did get the bolt and spade terminal to detach. I had to cut both positive leads away from the terminal in order to get it to spin on the battery just to get it off. I could not believe how much corrosion had occurred since I thoroughly cleaned it last year. It looked like something that had been dredged up from the bottom of the sea after a century or two.

Putting the new cable on was pretty simple. I followed the Service Manual instructions. But it was kind of aggravating to get to the starter solenoid under the car (hint: drive the car onto ramps and jack the car up BEFORE hacking up the battery cable and removing the battery). About an hour of work and now my battery cable looks brand new (except it's black instead of the OEM red color). No more defaulting to odometer and other anomalies.

Just thought you guys might be interested.

 

Thanks for the heads-up!

I generally check the cables every week-end because I pop the hood after every trip. (Obviously, it's not my daily driver, just a fun car).

I haven't seen any corrosion on this battery yet, but I will keep a closer eye on it.

Thanks!!!!

 

Thanks for the post, great info.

 

I put 04 (top terminal) cables on my 02 as i needed a new battery anyway.

 

I would like to echo this point. A genuine PITA getting at and getting off...that solenoid nut. On my 2000 there's a sensor in the way leaving virtually NO room for a wrench. - Fortunately the nut is not on very tight.

1/2" small wrench --- jack it up, take the wheel off, shine a light from up top (under the hood).....and contort yourself under there with that 1/2" wrench. Then you can wrestle with the clips near the firewall keeping the positive with the negative. (I replaced only the positive)

 

Moved to C5 Tech. This is an 11 year old thread, but will let it go to see if any additional new info can be added.

 

So, this wasn't in C5 Tech? That's the forum I chose to search in Advanced Search.
I would assume that changing battery cables will start to be necessary about now (or sooner). My positive got ruined from a leaking side post (a previous battery to the one in the car now).
The new info here is the 1/2 wrench. (it's handy to know that before getting under the car)