• Got the Contributing Memberships stuff finally worked out and made up a thread as a sort of "How-To" to help people figure out how to participate. So if you need help figuring it out, here's the thread you need to take a look at -> http://www.corvetteflorida.com/forums/showthread.php?t=3581 Thank you, everyone! Rich Z.

CHARGE SYSTEM FAULT

Rich Z

Rich Z

Internet Sanitation Engineer
Staff member
Looks like I may be needing a new alternator and/or battery.

On Sunday the wife and I took a drive out route 20 from Tallahassee heading towards Hosford so we could catch route 65 down through Sumatra and then back along 98 to head on back home. Nice long scenic drive with my new headers.

Anyway, we were nearly into Hosford when I noticed my voltmeter, which normally registers 14 volts, had dropped down to showing 12. Never saw that before, so I got a bit of wimplash at the thought of being out in the boonies (there is NOTHING along route 65!) and having the car die on me. So we turned around. The meter jumped back to 14 volts and stayed there the whole ride back home.

But this morning, I had to go to the courthouse to report for jury duty. Nothing unusual happened TO the courthouse, but when I started the Z up when I got out of there, I immediately got a CHARGE SYSTEM FAULT displayed. Uh oh....... I think I am getting the warning signs.

Well the car had 58K miles on it when I bought it, and I know alternators and batteries don't last forever in the Florida heat, so I guess an ounce of prevention may be worth 10 pounds of cure here. I REALLY hate to have a vehicle crap out on me during a trip, even if it would be just to go to the post office.

I just hope the Corvette doesn't take some special limited edition alternator with a $400 price tag on it..... :o
 
Rich, I get the charge system fault message every now and then. I've recently replaced my battery with an Optima Red Top and still got the message yesterday. I need to learn how to look up the codes on the DIC.

EDIT: I see you've posted the procedure in another thread. Thanks.

Scott
 
Well, just got back from Champion Chevrolet. The vette tech there (Shane) was all embarrassed to tell me that he had neglected to tighten down a ground screw for the alternator and that was most certainly causing my problems. I was just glad it wasn't something serious, so he had no need to be so apologetic about it. Sure beats paying for a new alternator!

But on the way home, I was eyeballing the voltmeter and saw that it was creeping down below 12 volts again. I pulled into the driveway and just sat there with the A/C running and put on the headlights to see what would happen. The voltage dropped down to 11.2 volts. I just revved up the engine a little bit, and could actually hear the alternator click in, and the volts started climbing back up to the normal 13.5 volts.

So has anyone actually paid attention to this meter? Does the voltage fluctuate like this normally? Honestly I NEVER paid attention to this meter before, so I don't have any idea if this is something that has ALWAYS been happening, and I just never noticed it. I guess it's kind of like your temperature gauge. It will go up and down while driving in traffic on a hot day, but heck, I don't really watch that one either.

:confused: :confused:
 
Mine never goes below the high 13...., whatever. I'd keep my eye on it. The electrical system on these cars are finicky...........Tom:)
 
Yeah, well that's what worries me. Up here in north Florida there are some areas where a breakdown could be embarrassing. I don't think the cell phones even work in some areas, so that would mean hoofing it leaving the vette alongside the road. NOT what I would really want to be doing.....

The vette tech did say he forgot to tighten that ground, but that doesn't mean it's not just a coincidence and I really do also have another problem related to the alternator. Especially an intermittent one, which would probably be a pain in the butt to try to catch and diagnose.

Something tells me the Corvette alternators are not cheap, so I really don't want to do the trial and error replacement routine.
 
Might have run the battery down with the loose ground not charging. Any idea how old the battery is, might be worth buying a new one.
They give no warning when they stop cranking Rich.:(

Jack
 
Yeah, looks like a remanufactured unit is $400. :eek:

I really don't know how old the battery is since I have only had the car since the end of September. And never looked at it too closely to see if it has a date code on it.

I was just leafing through the maintenance manuals for the car and see that GM considers the battery voltage to be acceptable if it is between 8.3 and 16.5 voltes (or thereabouts). So far I haven't found any indication that a fluctuation while driving of 2 to 3 volts is considered normal or not.

But it does seem to me that we had a similar situation with our Chevy Astro van where the voltage was fluctuating quite a bit. Then the alternator died.

Darn, I hate like hell to have to put it in the shop again so soon. But I'm going to be nervous taking it on a trip anywhere. I'll bet getting a tow truck hooked up to the Z is not going to be an easy task, and no telling what experience level the guy in the truck will have. Sigh.......
 
Well, yesterday I pulled the plug off of the alternator and sprayed both the male and female ends with some electronic contact spray cleaner I had around here. Then plugged and unplugged it a couple of times to see if that would clean off any oxidation that might be causing that intermittent problem I have been having. I saw that there is a plug on the starter in this circuit, but I couldn't see it from topside of the engine, and I don't really have any way to get underneath the vehicle to do that.

Today the wife and I took a drive down to Alligator Point, which was a nice 2 hour round trip. Didn't see a hint of a problem monitoring the battery voltage. Tended to stay right around 13.5 volts but did drop down as much as 13.2 and up to 13.7 while driving. When I pulled under the carport when we got home, it was setting at 13.0, but I think that is just the way it is. Although I am wise to the ways of Murphy's Law, I am hoping that maybe the problem is fixed. It just FELT like an intermittent contact to me upon thinking about it and reading up on how the circuitry works a bit in the maintenance manuals.

Anyway, we'll see, I guess. Just got my fingers crossed.
 
exile said:
Mine never goes below the high 13...., whatever. I'd keep my eye on it. The electrical system on these cars are finicky...........Tom:)
Click to expand...

agree! Mind doesn't go down below 13's with all the stero stuff. I bought a red top and all is well. put a volt meter and look at it yourself. How old is your battery?
 
Well I just bought the Z back at the end of September and this is the battery that was in it. So I have NO idea how old it is.

I've been looking at the Optima batteries, but honestly I thought the yellow top would be the best bet for a car driven at least once every several days. I thought the red top was for when people wanted to store their car for a month or three. But seems just about everyone I see is using the red top.

What am I missing?

In any event, I am pretty certain that the loose ground cable caused the SYSTEM FAULT message and quite likely the error code that got tripped. I am fully prepared to believe that this just might be a malicious coincidence and perhaps that plug just needed to be reseated. In the meantime I will keep my eyes peeled for a good price on a new alternator and maybe even a battery. Just in case.
 
Yep, battery is pretty cheap insurance. I bought my 02 Z 3 years old but only 4500 miles. Looked like a garage queen. I put a new redtop in it within a week of buying. I feel so much better knowing it's a new redtop:) ...........Tom
 
Rich

Yellow Top Optimas are more for heavy drain situations, running stereo systems while car is not running etc.
Red Top would be your first choice IMO, a little lighter also then the Yellow Top.
Just remember on the stock battery, they give no warning before dying.:(

Jack
 
Yeah, I hear you. We used to get our batteries from Sears for all of are other vehicles, but I learned the hard way why that call them "Die Hards" :rolleyes:

I've also read here and there about the OEM batteries leaking occasionally, so yeah, maybe I should look into one of those Optima red tops. Heck, it would match my engine anyway. Can't have the colors clashing under the hood, now can I?
 
Well, I had my battery replaced yesterday. After doing some digging around for info, I decided to go with the Exide Orbital battery (http://www.exide.com/products/automotive/exide_select_orbital.html).

I haven't driven it enough to make any proclamations about the product, but it does seem that my battery voltage reading was very stable for the drive home. Pretty much stayed pegged at 13.7 volts the entire time.

I don't know, maybe the old battery was just getting ready to give up the ghost and was kind enough to give me some warnings. I had a couple of sluggish starts the last week or so, and today when I started it up to run out to have the battery replaced, it was only registering 11.2 volts on the readout.

Well, we will see, I guess. At the very least, I don't have to worry too much about battery acid leakage with this guy.
 
:ahh: :ahh:

I think this problem STILL is not licked! Yesterday the wife and I drove over to Cape San Blas, about a 5 hour trip all today. I wanted to give that tune from the Predator a fair test at regular driving speeds. Anyway, I kept my eye on the battery voltage the entire time, and it hardly wavered at all from 13.5 volts. There was a period of time when it went up to about 14.5 volts however.

Anyway, I decided to run to the post office today, and I did decide to goose it a bit to see how the tune was working out. Didn't really do anything EXCESSIVE, but just rev'd the first couple of gears out to around 5K rpm. Anyway, when I resumed normal driving, I noticed that the voltage had dropped down to 11.8 volts. It fluctuated by a tenth of a volt for a while, then seemed to gradually creep lower. All total I drove about an hour to hour and a half just to the post office and back, and by the time I got back home, the voltage was reading 11.2 volts.

I dunno, but that just doesn't sound right to me. I'm guessing that the alternator is not charging up the battery, or just barely so. What do you guys think? And is there anything tough about replacing the alternator? It looks like just two bolts and a plug on the harness to me. But I'm not exactly sure how to loosen up that serpentine belt.......

Damn, always something........ :banghead:
 
Rich Z said:
I dunno, but that just doesn't sound right to me. I'm guessing that the alternator is not charging up the battery, or just barely so. What do you guys think? And is there anything tough about replacing the alternator? It looks like just two bolts and a plug on the harness to me. But I'm not exactly sure how to loosen up that serpentine belt.......

Damn, always something........ :banghead:
Click to expand...

Rich, as far as the serpentine belt goes, just follow the belt from the alternator around and you'll see a tension pulley? For lack of a better term. Just slap a wrench on that and it'll move to take the belt off or put on. Ivo and I replaced mine yesterday when we were doing the header install. If I have time tomorrow, I'll post a thread with pics and everything including the mod party. Right now, I have to get some sleep before work tonight!

Enjoy!
 
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