Saturday, May 8, 2010

Changing a Battery in a C5 Corvette and Charge System Fault error

Above is my home made "memory tool" that keeps the many settings in car radio when you are changing the battery.  You can buy these with the male 12 volt car outlet connector on it with a 9v volt connector for about $17.   Or, if you are like me and cheap, you build your own with two 6 volt lantern
batteries, put them in a series for half the price.  What I like about this is it is 12v and a greater amperage if you take longer than expected to change your car battery.  I do not like to waste my time resetting 24 of my favorite radio stations and the many settings inside today's car radios.  With today's aftermarket car radios, you have so many different devices that you can connect, that after you get everything working perfectly, the last thing you want to do is re-enter all of that back in just because you needed a new battery or had to clean some corroded connections on your car's electrical system.

I am documenting this because my C5 Corvette was getting random "Charge System Fault" warnings on the Driver Instrument Console and I decided to fix it today.  I had a 6 year old Optima battery that was in there and I decided to spend $110 and get a Sears DieHard Gold instead this time.  Sears stopped selling the Optima because (as I was told by multiple Sears employees) Sears had too many exchanges of Optima batteries over the years.  I did get 6 years out of mine, so I can not complain.  I also steered away from Optima because of the less than pleasant experience I had with Optima when my oldest son had a problem with his Optima.  Luckily, Advance Auto was very nice and took back the faulty Optima after I went up there with him.

On a C5 Corvette, there are two possible outlets to plug your memory tool into.  You want to use the 12volt outlet in the arm rest as that is unswitched.  The 12 volt connector below your radio is switched.  What this means if you plug your memory tool into the 12 volt outlet below the car radio, it can not provide the 12 volts to the overall system to keep all the settings in your car radio because it is switched off when the ignition is turned off.   Use the 12 volt outlet below the arm rest which is unswitched.

Above is a photo of the switch near the front bumper that is for the hood light that comes on with a switch when the hood is raised.  You want to unplug this as well because this will needlessly eat up the power from your memory tool.

Above is the light built into the hood that should be off.

Above is a photo that is in the lower right of the C5 battery compartment.  Because of this location, it has a tendency to become corroded pretty quickly if you do not clean it right and protect it.  After you remove the battery (taking the ground off first, then the hot lead, then hold down bolt) you can clean this ground.  This ground is (naturally) tied into the ground lead that goes to the battery.

You should pull up on the plastic housing (nothing is keeping it down on the upside bolt above) and then take it off to properly clean it.  I would recommend using a Dremmel tool to get all the corrosion off both sides as well as running it through the center of the two round spade plugs that you will find.  Above you can clearly see the large black round spade plug and to the left you can see the silver looking wire that also has a round spade plug on it.  Clean them until they are shiny. Take a small metal brush to the actual bolt itself to make sure that is clean.  When you are done, make sure you get all the metal shavings and corrosion off with a clean rag.  I like to use denatured alcohol as well here, then dry it off.  The bolt will not get shiny as it is made of brass (I think).

Above is the finish product.  BUT, before you put the battery back in, clean up any corrosion that is in the bottom of the tray.  Also, take a good, close look at the inside of the positive (red) and negative ground (black) connectors.   There is likely corrosion on those connectors as well.  Clean them up with a good metal brush until they are shiny.  Remember that ground is first off and last on when you are dealing with a car battery.
Above is Corrosion Block and is what I prefer to use to keep corrosion away on battery terminals and ground points in a car.  It is highly recommended by the boating crowd and has worked out well for me.

With my Corvette, there were multiple issues that could have been causing the "Charge System Fault" warnings on the Driver Instrument Console:
  • The two round spade connectors that go to ground in the lower right of the battery compartment were very corroded.
  • The positive or hot connector on the battery was slightly corroded.
  • The Optima battery was 6 years old and probably on the slow death spiral.
Everything is perfect now :-)