Alternator/battery voltage ....need help!
Thread Starter
Pro
Joined: Feb 2006
Posts: 718
Likes: 7
From: Jacksonville , NC
Alternator/battery voltage ....need help!
Was driving around town yesterday in my 02 vert 68K and noticed that the voltage gauge was reading less than 11 volts, DIC confirmed that voltage was 10.9 volts. I drove home (about 20 minutes) voltage remained constant at 10.9 volts.
As I turned onto my street the voltage climbed up to 13.5.
When I got home I measured the voltage of the battery with the car off 11.17
Started the car and voltage was reading 10.9 on the gauge and DIC
Took a voltage reading from the red terminal on the back of the alternator and it read 14.35
I charged the battery over night (reading 12.5 and load tested, checked good) and started the car this morning and it is still reading 10.9 volts on the gauge and DIC, 14.35 on the alternator.
I checked the connections on the starter, the ground above the starter on the block and the ground under the battery box.
No codes on the DIC and no charging system fault message.
Any info on troubleshooting or known fixes would be appreciated
Thanks in advance for any input
As I turned onto my street the voltage climbed up to 13.5.
When I got home I measured the voltage of the battery with the car off 11.17
Started the car and voltage was reading 10.9 on the gauge and DIC
Took a voltage reading from the red terminal on the back of the alternator and it read 14.35
I charged the battery over night (reading 12.5 and load tested, checked good) and started the car this morning and it is still reading 10.9 volts on the gauge and DIC, 14.35 on the alternator.
I checked the connections on the starter, the ground above the starter on the block and the ground under the battery box.
No codes on the DIC and no charging system fault message.
Any info on troubleshooting or known fixes would be appreciated
Thanks in advance for any input
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
The voltage readings on the DIC and IPC voltmeters are NOT actual battery voltage!
The reading that those two meters provide are voltage that go thru and happen after the ignition switch. If the contacts inside the ignition switch are dirty/burnt. defective/ FUBAR/damaged,,, you will get something LESS than actual battery voltage.
SO,,,,,,,,, if you see 11.5 VDC on the IPC meter, you may very well have 14.5 VDC on the battery and alternator outputs.
BC
The reading that those two meters provide are voltage that go thru and happen after the ignition switch. If the contacts inside the ignition switch are dirty/burnt. defective/ FUBAR/damaged,,, you will get something LESS than actual battery voltage.
SO,,,,,,,,, if you see 11.5 VDC on the IPC meter, you may very well have 14.5 VDC on the battery and alternator outputs.
BC
Thread Starter
Pro
Joined: Feb 2006
Posts: 718
Likes: 7
From: Jacksonville , NC
Check all your battery connections to make certain they are clean and tight. That includes the connection at the starter. Caution there since the starter is electrically hot all the time. Check battery voltage across the battery posts with the neg cable disconnected (ie no load). If it is not near 12.7 volts you should put it back on a charger and get it fully charged. A good battery at full charge should measure 12.7 to 12.9 volts or more. If you cannot charge it to 12.7 volts no load, it's on its way out.
If the voltage at the alternator is greater than at the battery then you may have a cable problem between the alternator and battery. I'll look for a Bill Curlee writeup I think I saved about this possible issue.
Here's the Bill C post that I was referring to above:
http://forums.corvetteforum.com/1569664280-post654.html
If the voltage at the alternator is greater than at the battery then you may have a cable problem between the alternator and battery. I'll look for a Bill Curlee writeup I think I saved about this possible issue.
Here's the Bill C post that I was referring to above:
http://forums.corvetteforum.com/1569664280-post654.html
The voltage readings on the DIC and IPC voltmeters are NOT actual battery voltage!
The reading that those two meters provide are voltage that go thru and happen after the ignition switch. If the contacts inside the ignition switch are dirty/burnt. defective/ FUBAR/damaged,,, you will get something LESS than actual battery voltage.
SO,,,,,,,,, if you see 11.5 VDC on the IPC meter, you may very well have 14.5 VDC on the battery and alternator outputs.
BC
The reading that those two meters provide are voltage that go thru and happen after the ignition switch. If the contacts inside the ignition switch are dirty/burnt. defective/ FUBAR/damaged,,, you will get something LESS than actual battery voltage.
SO,,,,,,,,, if you see 11.5 VDC on the IPC meter, you may very well have 14.5 VDC on the battery and alternator outputs.
BC
Thanks Gents,
I will check the voltage at the battery to ensure that the battery is being charged when the car is running, and I guess I will be removing and cleaning the contacts in the ignition switch.
Will report back when complete.
Thread Starter
Pro
Joined: Feb 2006
Posts: 718
Likes: 7
From: Jacksonville , NC
Problem Solved....Thanks!!
Good News
The cleaning of the ignition switch went without a hitch. My switch looked exactly what Bills and others looked like. About an hour and a half total for the R&R.
Bad News
The switch wasn't the problem, although I feel better about the ignition switch contacts after cleaning them
Good news
Found the problem....loose terminal wires on the starter.
Bad News.
It was a PITA to tighten the nut without dropping the exhaust.
Best News
The Vette is back up and running perfectly. 14.6 volts at the battery while running, 14 volts on the gauge and DIC, and most importantly, the car starts every time!
Thanks Gents for the information and insight to resolve this problem.
Image has nothing to do with the topic, but console **** is always good!
The cleaning of the ignition switch went without a hitch. My switch looked exactly what Bills and others looked like. About an hour and a half total for the R&R.
Bad News
The switch wasn't the problem, although I feel better about the ignition switch contacts after cleaning them
Good news
Found the problem....loose terminal wires on the starter.
Bad News.
It was a PITA to tighten the nut without dropping the exhaust.
Best News
The Vette is back up and running perfectly. 14.6 volts at the battery while running, 14 volts on the gauge and DIC, and most importantly, the car starts every time!
Thanks Gents for the information and insight to resolve this problem.
Image has nothing to do with the topic, but console **** is always good!
