CHARGE SYSTEM FAULT

**Rich Z** · 04-18-2006, 12:26 PM

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.....

**Rich Z** · 04-18-2006, 12:33 PM

Well duh! This error I had earlier on the DIC might be significant as well:

Quote:

P1637 H - Generator L - Terminal Circuit.

MADN3SS · 04-19-2006, 06:54 PM

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

**Rich Z** · 04-19-2006, 07:14 PM

I think this thread may help you..... http://www.corvetteflorida.com/forum...hread.php?t=31

What I would like to see is an actual troubleshooting guide linked to those codes. I have the maintenance manuals for my 2002, but honestly haven't even cracked them open yet. Maybe something like that is in one of them....

**Rich Z** · 04-20-2006, 03:07 PM

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.

exile · 04-20-2006, 11:39 PM

Mine never goes below the high 13...., whatever. I'd keep my eye on it. The electrical system on these cars are finicky...........Tom

**Rich Z** · 04-21-2006, 12:14 AM

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.

gsjack · 04-21-2006, 12:30 AM

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

exile · 04-21-2006, 12:39 AM

http://www.zip-products.com/Zip/prod...332D906A5BC775

**Rich Z** · 04-21-2006, 02:39 AM

Yeah, looks like a remanufactured unit is $400.

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.......