Alternator Help.."98" C5 Coupe
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 925
Likes: 4
From: EXTON PA
Alternator Help.."98" C5 Coupe
Alternator and the voltage gage read a 13.5-14 at the start of the engine but after a 3-5 mintue idle the voltage starts to drop by .1 at each change until I reach sub 13. Each drop would show a flashing voltage number on the DIC going from a number to a number that was lowered by .1. Have a small auto charging system analyzer from Motormite that shows no problem with the alternator. I use a trickel charger to bring battery back to a full charge. New Red Top battery. DIC Codes that are present c1226/c1233/c1255 and b2527/b2723
Any reason for the problem other than the alternator.
Any reason for the problem other than the alternator.
Last edited by kg54trains; Aug 8, 2009 at 10:59 AM. Reason: corrected information
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
Run a "temporary" 10ga wire from the BATT terminal on the back of the alternator to the POSITIVE battery on the battery. Let me know if this improves or eliminates the issue. Its best to crimp on some eyelet terminals so that the wire is nice nice and secure and makes the proper connections.
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Bill, I've never heard of a flashing voltage indication in the DIC. That's strange. I'm wondering if he's not got the engine high enough to generate sufficient charging such as driving in town, fans are on and so on. Obviously the connections at the solenoid will be possible suspect if the wire makes a change. Battery cable crimp connections?
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
Well,,,now you made me commit to a diagnosis that I really didn't want to throw out until he did a little bit of investigating but, here goes.
The volt meter on the IPC does NOT show ACTUAL battery voltage
It shows the voltage on the "HOT AT ALL TIMES" busses that come off the engine compartment fuse box B+ terminal.
That buss supplies voltage to the IGNITION 1 Circuit. That circuit goes thru "Instrument Panel Electrical Center,,, MAXI Fuse# 45 (60 amps)". From there it goes thru the "IGNITION SWITCH"! The IGNITION SWITCH supplies voltage to the IPC.
See,,,you made me blame the damn ignition switch already and the OP hasn't even written back ONE word!
,,,,,,
See ,,,you knew that I was going to recommend that all along, didn't you?!
Now your going to make kg54trains read a whole different post and then do some work!
http://forums.corvetteforum.com/c5-t...ch-repair.html
See,,I blaming this all on you.
Im leaning toward a defective ignition switch. Clean it and you should be as good as new!
kg54trains. If the ignition switch solves the issue,,please post in my ignition switch post. Im keeping tract on how many of these are becoming issues.
BC
The volt meter on the IPC does NOT show ACTUAL battery voltage
It shows the voltage on the "HOT AT ALL TIMES" busses that come off the engine compartment fuse box B+ terminal.
That buss supplies voltage to the IGNITION 1 Circuit. That circuit goes thru "Instrument Panel Electrical Center,,, MAXI Fuse# 45 (60 amps)". From there it goes thru the "IGNITION SWITCH"! The IGNITION SWITCH supplies voltage to the IPC.
See,,,you made me blame the damn ignition switch already and the OP hasn't even written back ONE word!
,,,,,, See ,,,you knew that I was going to recommend that all along, didn't you?!Now your going to make kg54trains read a whole different post and then do some work!
http://forums.corvetteforum.com/c5-t...ch-repair.html
See,,I blaming this all on you.
Im leaning toward a defective ignition switch.
Clean it and you should be as good as new!kg54trains. If the ignition switch solves the issue,,please post in my ignition switch post. Im keeping tract on how many of these are becoming issues.
BC
Last edited by Bill Curlee; Aug 8, 2009 at 01:15 PM.
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Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 925
Likes: 4
From: EXTON PA
Run a "temporary" 10ga wire from the BATT terminal on the back of the alternator to the POSITIVE battery on the battery. Let me know if this improves or eliminates the issue. Its best to crimp on some eyelet terminals so that the wire is nice nice and secure and makes the proper connections.
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
It does eliminate the issues. The guage will show 13.8-14.0 at start up and under a load of Headlights/Stereo the guage reading is 13.7-13.8. Ran the car with a load for 15-20 mins. If this is a alternator problem that will require replacement can you suggest a manufacture. GM is Mid-300 from gmpartshouse, and there are varies others down to 200. I will be also completing the ignation switch rehab but the heat/hum in the last week in SE PA has been tough. I hope this weather change does not continue because generally the weather is the same as Central PA. Do not need frying pan heat for that last weekend in August.
Thanks
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
If the jumper fixes the issue,,,,,you DO NOT have an alternator issue. You have an issue with the wiring from the alternator to the battery. The RED wire on the BATT connection goes to the solenoid. From the solenoid, it goes to the battery. If theres corrosion or a loose connection, those are the symptoms that you will see.
Use a DC Volt meter and with the engine running, read the positive battery terminal to the BATT terminal on back of the alternator. It should read ZERO volts DC. The more voltage it reads, the worse the connection is between the battery and alternator.
If you get any voltage, examine the solenoid and the wiring on the solenoid terminal.
BC
Use a DC Volt meter and with the engine running, read the positive battery terminal to the BATT terminal on back of the alternator. It should read ZERO volts DC. The more voltage it reads, the worse the connection is between the battery and alternator.
If you get any voltage, examine the solenoid and the wiring on the solenoid terminal.
BC
3rd Gear
Joined: Aug 2008
Posts: 3
Likes: 0
I am having the same problem however my 98 C5 ends up dying after a few minutes of driving. I can jump it off and it will crank but then shortly after the gauges fell first then the car dies. I went to buy a new battery and was able to make a 40 minute drive home but now car is dead. Sounds like alternator i know but charge system failure has been flashing across the screen off and on for two years now and will drop a charge during this time. Thus I think mine may be a bad connection somewhere too? Any thoughts? And where is the solenoid located? Thanks so much
Le Mans Master
Joined: Apr 2002
Posts: 6,927
Likes: 3
From: Glendale NY
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18- '19
information....
Run a "temporary" 10ga wire from the BATT terminal on the back of the alternator to the POSITIVE battery on the battery. Let me know if this improves or eliminates the issue. Its best to crimp on some eyelet terminals so that the wire is nice nice and secure and makes the proper connections.
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
Im trying to figure out if you have a compromised charging circuit from the alternator to the battery. Ive also used a battery jumper cable to do the test curb side.
BC
I can't believe (although I should) that I'm still copying information. You have been helping forum members with For Years.
Thanks pal
Bob (210,000 miles)
Last edited by 6SPD98; Nov 6, 2009 at 12:23 PM.
3rd Gear
Joined: Aug 2008
Posts: 3
Likes: 0
You guys are awesome, its amazing the knowledge on here.
So I did thread #2 on here and ran a wire directly from the positive post on the alternator to the positive post on the battery and the car is showing good charge. So now I know it is the wiring. Where should I start checking the wiring and where is the solenoid? Thanks so much.
So I did thread #2 on here and ran a wire directly from the positive post on the alternator to the positive post on the battery and the car is showing good charge. So now I know it is the wiring. Where should I start checking the wiring and where is the solenoid? Thanks so much.
