Tar Heel

We don't drive our C5 much but recently took it on a long trip. Coming home the car died. Long story short but it displayed the message charge system fault, service engine soon, and many other messages related to traction control and ABS. Finally I lost everything on the dash except the heads up and shortly thereafter the car died. After a very expensive tow home I started researching the message. Too be honest I believe I checked everything it could be. Took the alternator off and had it checked at several auto stores. Everyone said it was ok. Battery is a red top Optima that's 2.5 years old. Had it checked too. They said it was fine but "in the last 25% of it's life". It stays of a Ctek battery charger 24/7. Cables are tight on the terminal, alternator and starter. Nothing is visually rubbing on anything or worn through the cable cover. Starting the car it still says check system fault and the DIC tells me the alternator is putting out 11.8 volts. I'm going to read more posts to make sure I've checked everything but any ideas before I have it looked at by the stealership. I hate to go that route but am close to being out of ideas.

Thanks.

Scott

My Vette Life

Try using the search in the forum. This forum is flooded with topics like this and codes too.

Your issue is a typical c5 issue.

Chances it's the battery.

Macleod52

Fully charge your battery and take a mulit-meter and see what the reading is on the battery itself. A good battery should read 12.7-12.9v. If your battery is on it's last leg w/25% life left (what is used to determine that in the first place) then that may be where i would start. I wouldn't replace the battery but I would make sure it's fully charged and use a digital multi-meter to read at the battery posts. If you are at 12.5v or below then I would replace the battery and see if that solves your problem. If that doesn't fix your problem then you would want to start looking at other things.

The C5 is very picky when you have low voltage. If you're sitting at 12.5 or below and the battery is fully charged you will start throwing all sorts of codes.

Beyond that I will let Bill Curlee chime in as he's the C5 electrical guru.

Also, pull all your codes and post them (you can search in google or youtube for a how to video). The codes will help us determine if something else may be going on.

Tar Heel

Thank you. I'll start with the reading the battery and codes and post my results and go from there. I've done a search and literally read everything to do with a charge system fault. My concern is that it could be the battery, alternator, starter, cables ... and on and on. I'm not sure how they determine that the battery is on its last 25% of life and really don't know how a $200 Optima lasted only 30 months when the car is never driven and stays on a charger. When they told me that I was surprised and had never heard that one before.

Scott

lionelhutz

read and do what was posted directly above.

If the battery can start the engine then the alternator should start working to produce the correct voltage.

And the battery voltage drops WELL below 12.5V every time a C5 is started yet every C5 doesn't throw all sorts of codes when started.

Never driving and constantly using a non-Optima specific tender is a good way to shorten the life of an Optima. Well, besides them being nothing special anymore to begin with. Tons of other AGM batteries out there that are easily just as good. You're better off charging the battery for a day every 2 weeks or so. Or use a timer on a tender and run it a couple of hours a day or 12 hours once a week or something like that.

marco383

What is unique about an "Optima specific" battery tender? I use one that drops the charge rate off as the battery charges, so what am I missing?

lionelhutz

Ask Optima. They're the ones who say you should use a maintainer with a AGM specific setting.

Bill Curlee

You really need to use an actual multimeter and read the battery directly at the battery terminals, and read the B+ terminal on back of the alternator.. Engine OFF and Engine RUNNING. The B+ terminal on the ALT and the POS terminal on the battery SHOULD be the same voltage to chassis ground.

Compare that/those readings to what you see on the IPC Voltmeters and report findings.

I agree......... Leaving the charger on the battery 24/7 is not a good idea. There are chargers that STATE that they can be left connected but, it still can over charge the battery and or boil out the reserve electrolyte.

Tar Heel

Thank you gentlemen for the help. Got the car up in the air to visually inspect things and went out last night and picked up a new multimeter. I did notice just looking over things that the end of the red cable from the back of the alternator to the starter appears discolored over the last couple inches where it attaches to the starter. It's not red but a gray color. After our long trip I'm fairly certain the tremendous heat from the headers has "injured" that cable. This weekend I'll check the battery and alternator output with my multimeter and will also go from the alternator to the battery as I've read in other posts to see if there is any change in voltage. Again, I'm guessing it's the wire so I'll need to pull the header and starter and replace that wire from the alternator.

I suppose from now on also I won't leave the Ctek charger working 24/7. I thought that what these chargers were made for and I've never had an issue doing this before. I've done it with three cars and our RV over the last several years and never had an issue.

Scott

lionelhutz

There are actually 2 wires from the alternator connecting to at the starter solenoid. The small red wire comes from the alternator connector and has a grey fusible link. The large red wire comes from the stud on the alternator and has an orange fusible link.

Actually take the connection apart, clean the wire terminal rings with some emery cloth and put it back together. Spread a little grease on the connection if you want to try protecting it.

The easiest way to check the wiring is connecting the meter with one lead on the alternator output stud and the other lead on the battery positive terminal. The voltage you measure should be well under 0.5V when the engine is idling without any heavy loads turned-on (no heater, lights, cooling fans). Otherwise, you have a connection issue.

Tar Heel

Took a minute last night to get my meter out and check some things. Battery (with car off) was 12.7. Alternator with the car running was 14 and change. Connected the alternator to the battery and was getting 2.6. Car also threw a P0622 code.

Guess I need to get under it now and check the connection on the starter stud?

Scott

GCG

It seems your battery and alternator are fine, but that 2.6v voltage drop strongly suggests that you need to check the connection on the starter solenoid

Tar Heel

Well, I believe that I have solved the mystery. I crawled under the car again to inspect the connections on the starter. The stud that holds the three positive wires was completely broken off the starter. Anyone ever seen this before? I know I haven't and don't have any idea what could have caused that. ??? Took the header off in order to remove the starter. I'll pick a new one up tomorrow and try to get it all back together tomorrow after work. Really curious how that bolt completely broke off. Weird.

Scott

Bill Curlee

The plastic insulator gets brittle from heat and age and can be cracked and broken easily. Just get a new solenoid or remanufactured starter and all should be well again.

C

Tar Heel

Thank you Bill. I think since the starter is kind of a pain to replace with headers and is 13 years old I'll just do the whole starter. Would you recommend I switch over to a 2 long bolt starter? If so would you happen to have a part number? I have an O'Reilly, Autozone, Advanced and ABC local.

Scott

Bill Curlee

Long bolt starter YES... Sorry.. I don't have the part number.

Tar Heel

Thank you Bill. I'll research that and go with the long bolt starter.

Scott

Tar Heel

Ordered a new Bosch long bolt starter from Rock Auto for $113 shipped with no core and a lifetime warranty. Got it installed tonight, reinstalled the header and buttoned everything back up. Not too bad of a job. Car started right up, no codes, no charge system fault, no service engine soon. DIC reads 14.1 volts. Very happy everything seems right now. I'm curious how long it's been going bad and if that hindered the performance at all.

Scott