Battery / Alternator question
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
Likes: 0
From: South Carolina
Battery / Alternator question
02 Corvette coupe, 6 speed, 97k miles
Two days ago I was driving on the highway and I got the "Charge system fault" error, all of the electronics started to shut down and then the car died. I had it towed to the Chevy dealer and they said the battery and alternator were shot.
I replaced both of them, everything is tightened down and I cleared all the codes.
The car seems to be charging the battery now, battery voltage is hanging around 13.5-13.7 while under load. But when I go into neutral it drops to 12.5-12.7.
Is this normal operation and I'm just being paranoid? The only codes that come up now are PCM 1638H and HVAC 0338 C (HVAC code has been on the car forever)
Thanks in advance
Two days ago I was driving on the highway and I got the "Charge system fault" error, all of the electronics started to shut down and then the car died. I had it towed to the Chevy dealer and they said the battery and alternator were shot.
I replaced both of them, everything is tightened down and I cleared all the codes.
The car seems to be charging the battery now, battery voltage is hanging around 13.5-13.7 while under load. But when I go into neutral it drops to 12.5-12.7.
Is this normal operation and I'm just being paranoid? The only codes that come up now are PCM 1638H and HVAC 0338 C (HVAC code has been on the car forever)
Thanks in advance
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I agree! The IPC analog voltmeter & the DIC Digital Voltage reading are NOT giving you actual battery/charging system voltages.
Read the BATTERY & Charging System Voltage directly on the battery terminals.
If you have a 1998 - 2003 C5, the battery cables MUST be properly tightened on the battery. IF, you can move the side terminals by hand,, there TOO LOOSE.
The connection of the BATTERY POSITIVE CABLE to the ALTERNATOR BATT Terminal is not a complete end to end connection.
The POS wire/cable from the battery goes down to the starter SOLENOID main terminal and the BATT Wire (ALT OUTPUT) from the back of the alternator also connects at that terminal on the starter solenoid.
IF,,, that terminal is loose, corroded, damaged burnt,,,,, You will have improper and inconstant charging voltages.
BC
Read the BATTERY & Charging System Voltage directly on the battery terminals.
If you have a 1998 - 2003 C5, the battery cables MUST be properly tightened on the battery. IF, you can move the side terminals by hand,, there TOO LOOSE.
The connection of the BATTERY POSITIVE CABLE to the ALTERNATOR BATT Terminal is not a complete end to end connection.
The POS wire/cable from the battery goes down to the starter SOLENOID main terminal and the BATT Wire (ALT OUTPUT) from the back of the alternator also connects at that terminal on the starter solenoid.
IF,,, that terminal is loose, corroded, damaged burnt,,,,, You will have improper and inconstant charging voltages.
BC
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Checking the connections and actual battery voltage are good ideas but:
Guys, the way I see it even if the DIC is off it should not go down in Neutral in my opinion. I am wondering if it is a belt issue that is not driving the alternator enough when there is a lower load on it. Or the alternator is the issue somehow.
If I am off base please let me know. Just trying to wrap my head around the issue.
Mr. Sam
Guys, the way I see it even if the DIC is off it should not go down in Neutral in my opinion. I am wondering if it is a belt issue that is not driving the alternator enough when there is a lower load on it. Or the alternator is the issue somehow.
If I am off base please let me know. Just trying to wrap my head around the issue.
Mr. Sam
Instructor
Joined: Jun 2015
Posts: 111
Likes: 2
From: Brazil IN
I just did my alternator and then realized my idler/tension pulley was bad as well. It had a nice 3 degree lisp in it. I'd check that out as well. At least it is cheap and easy to replace. If you haven't replaced the belt in a awhile, it might be worth doing as well, since they are cheap.
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
Likes: 0
From: South Carolina
My tensioners seem okay, had to use a bit of muscle to get the belt back on the alt when I changed it and when I replaced the water pump a few months ago. If the tensioners were going out I'd have issues with power steering and cooling correct? Or at least some sqeaks?
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Instructor
Joined: Jun 2015
Posts: 111
Likes: 2
From: Brazil IN
The only reason I knew mine was bad was I had a free A/C check done on the car and the mechanic pointed it out. It was obvious after he pointed it out. Instead of being straight up and down, it was ****-eyes a bit. If I had left it, my guess is it would have worn on the side of the belt and finally caused the belt to pop off and tangle in the fan.
It had good tension on it, but not as good as the new one.
Might not be your issue at all, if you know yours is good. With a new alt, my volts are right at the 13.5 to 13.7 range expect when starting. But then I have a 4 speed auto, so don't put it in N.
It had good tension on it, but not as good as the new one.
Might not be your issue at all, if you know yours is good. With a new alt, my volts are right at the 13.5 to 13.7 range expect when starting. But then I have a 4 speed auto, so don't put it in N.
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
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From: South Carolina
Are we talking about the tensioner on the passenger side of the engine, right on top? Mines has a bit of a lean to it.
Played with the car a bit. The volts rise and fall with the engine rpms. Idling it stays around 12.0-12.2 rises with rpm and then stays steady at 13.7 anything over 2000rpm
Played with the car a bit. The volts rise and fall with the engine rpms. Idling it stays around 12.0-12.2 rises with rpm and then stays steady at 13.7 anything over 2000rpm
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
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From: South Carolina
Update
Replaced the battery with an optima red top. Got a second alternator, had it tested and it tested fine. Now the car says "charge system fault" and it won't charge the battery past 11v. I pulled the horn mini relay and plugged it back in and everything was charging normally. Then yesterday it started doing the same thing.
Codes are p1637 and p1638
Replaced the battery with an optima red top. Got a second alternator, had it tested and it tested fine. Now the car says "charge system fault" and it won't charge the battery past 11v. I pulled the horn mini relay and plugged it back in and everything was charging normally. Then yesterday it started doing the same thing.
Codes are p1637 and p1638
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
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From: South Carolina
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
our cars use a specific type of alternator. The car will act all kinds of wonky w/o it
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
You will just keep throwing money at it until you do some inspecting, troubleshooting and testing!!
Get a meter and when it fails,, read the BATT terminal on the back of the alternator to chassis ground, When the engine is OFF,, It should read full battery voltage. When the engine is running, it should read full charging voltage..
Read between the POSITIVE battery terninal and the BATT terminal with the volt meter. It should read zero volts.
BC
Get a meter and when it fails,, read the BATT terminal on the back of the alternator to chassis ground, When the engine is OFF,, It should read full battery voltage. When the engine is running, it should read full charging voltage..
Read between the POSITIVE battery terninal and the BATT terminal with the volt meter. It should read zero volts.
BC
Melting Slicks
Joined: Aug 2013
Posts: 2,491
Likes: 315
St. Jude Donor '15-'16-'17-'18-'19-'20-'21-'22
02 Corvette coupe, 6 speed, 97k miles
Two days ago I was driving on the highway and I got the "Charge system fault" error, all of the electronics started to shut down and then the car died. I had it towed to the Chevy dealer and they said the battery and alternator were shot.
I replaced both of them, everything is tightened down and I cleared all the codes.
The car seems to be charging the battery now, battery voltage is hanging around 13.5-13.7 while under load. But when I go into neutral it drops to 12.5-12.7.
Is this normal operation and I'm just being paranoid? The only codes that come up now are PCM 1638H and HVAC 0338 C (HVAC code has been on the car forever)
Thanks in advance
Two days ago I was driving on the highway and I got the "Charge system fault" error, all of the electronics started to shut down and then the car died. I had it towed to the Chevy dealer and they said the battery and alternator were shot.
I replaced both of them, everything is tightened down and I cleared all the codes.
The car seems to be charging the battery now, battery voltage is hanging around 13.5-13.7 while under load. But when I go into neutral it drops to 12.5-12.7.
Is this normal operation and I'm just being paranoid? The only codes that come up now are PCM 1638H and HVAC 0338 C (HVAC code has been on the car forever)
Thanks in advance
https://www.corvetteforum.com/forums...-b0338-hc.html
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 25
Likes: 0
From: South Carolina
Went to go secure the solenoid washers, entire bolt snapped off with very little pressure.This may have been the problem. I think the Chevy dealership didn't even look at the car when I dropped it off. Installed a new starter and the codes went away, battery is holding at 14v now
