Interesting Electrical Problem
Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
Interesting Electrical Problem
Last night I noticed I had a leaky battery. I think I caught it early as there wasn't too much acid built up and it hadn't really gotten down to the computer area yet. Using baking soda and water i cleaned the acid off the frame.
I noticed on the way home today (still on the old battery) I was only getting 11.7 on the volt gauge on the dash. Figured it was b/c the old battery had leaked out too much juice. After I changed the battery the volt readout didn't improve. In fact I lost a couple tenths. We're down to about 11.2-4 at this point.
The alternator is fairly new and everything was FINE until this battery situation began yesterday evening.
Any ideas on the source of this? I can't stand electrical problems.
**Edit, I also have no codes present either before or after the battery change.
I noticed on the way home today (still on the old battery) I was only getting 11.7 on the volt gauge on the dash. Figured it was b/c the old battery had leaked out too much juice. After I changed the battery the volt readout didn't improve. In fact I lost a couple tenths. We're down to about 11.2-4 at this point.
The alternator is fairly new and everything was FINE until this battery situation began yesterday evening.
Any ideas on the source of this? I can't stand electrical problems.
**Edit, I also have no codes present either before or after the battery change.
Last edited by TexVette01; Mar 24, 2014 at 11:06 PM.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
Low voltage readings on the dash gauges is often related to Ignition Switch issues. Here are a couple of links you should review carefully:
diagnosis
http://forums.corvetteforum.com/1568186703-post64.html
removal
http://forums.corvetteforum.com/1571067145-post107.html
repair procedure
http://forums.corvetteforum.com/c5-t...ch-repair.html
The first one requires a Digital Multi Meter to check voltages across some fuses that are AFTER the ignition switch. Compare those readings to the voltage measured directly across the battery. If there is more than a tent or two volts difference ( the fuse readings being lower than the battery readings) then you need to remove and clean the Ignition Switch.
diagnosis
http://forums.corvetteforum.com/1568186703-post64.html
removal
http://forums.corvetteforum.com/1571067145-post107.html
repair procedure
http://forums.corvetteforum.com/c5-t...ch-repair.html
The first one requires a Digital Multi Meter to check voltages across some fuses that are AFTER the ignition switch. Compare those readings to the voltage measured directly across the battery. If there is more than a tent or two volts difference ( the fuse readings being lower than the battery readings) then you need to remove and clean the Ignition Switch.
I know my HPtuners module doesn't communicate with the BCM and it's got a voltage monitor in it, so I assumed it came from the PCM.
OP, If you'll start the car, use your volt meter to go from various hot points to find your voltage drop.
If you put it on DC volts and go from the battery + post to the alternator hot post, it'll display the amount of voltage drop you have between those two points, Then also measure between the battery + post and the two red wires in in the weatherpack plug on the alternator.
Also I've seen people forget or not know to check the actual battery connections inside the rubber insulating boots and when they do, discover a mess of corrosion causing a high resistance connection, in turn causing the low voltage.
Let us know what you find.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 301
From: Columbia SC
My first step would have been to ditch a leaky battery and put in a new one. Then, if I had problems I would start to investigate.
My guess is the battery is bad and not just leaky.
Edit: Sorry I missed that you changed the battery. Too early in the morning for my brain to work. Even later it is still challenged. Glad your leakage was caught early.
My guess is the battery is bad and not just leaky.
Edit: Sorry I missed that you changed the battery. Too early in the morning for my brain to work. Even later it is still challenged. Glad your leakage was caught early.
Last edited by dadaroo; Mar 25, 2014 at 10:16 AM.
Safety Car
Joined: Mar 2005
Posts: 3,734
Likes: 1,203
From: Wisconsin
Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
Morning Update:
I now have code p1637 (h) and a service vehicle soon message.
On the initial startup this morning the volt readout on the gauge cluster was 11.7, when I got to work it was 10.7/8
I cleaned the two grounds under the battery tray as well.
I forgot too mention on Saturday when I went to start the car the starter motor sounded odd for a second. It's hard too describe...almost like it was just freewheeling or spinning with no resistance. But the car fired right up. The car also runs great.
I wonder if my baking soda/water treatment Sunday evening screwed with the connections on the starter???
And I had already changed the battery early Sunday. I couldn't Saturday night.
I now have code p1637 (h) and a service vehicle soon message.
On the initial startup this morning the volt readout on the gauge cluster was 11.7, when I got to work it was 10.7/8
I cleaned the two grounds under the battery tray as well.
I forgot too mention on Saturday when I went to start the car the starter motor sounded odd for a second. It's hard too describe...almost like it was just freewheeling or spinning with no resistance. But the car fired right up. The car also runs great.
I wonder if my baking soda/water treatment Sunday evening screwed with the connections on the starter???
And I had already changed the battery early Sunday. I couldn't Saturday night.
Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
Afternoon update: car is dead as a hammer. Going to change the alternator in the parking lot of Advance Auto. The voltage dropped from 11 to 9 then the dash went black. Car stalled shortly thereafter
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
You are not even sure the alternator is the problem. And you are not likely get the correct alternator from Advance. It will bolt up but you will most likely get charge system faults. If you need an alternator the best bet is to get yours rebuilt.
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 starter solenoid is the JUNCTION POINT for the alternator and the battery. If that wire is loose/burnt/ corroded, 100 alternators will NOT charge the battery.
Charge the battery back up. Get a meter and do some checking. The large terminal on the BACK of the alternator needs to read full battery voltage ALL THE TIME. If it doesnt, its NOt connected to the battery.
Bill
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Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
After a long afternoon i swapped the alternator in the parking lot and recharged the battery. Car ran fine all the way home (40 miles) and showed 14 volts on the dash. Never dropped below that even with the air conditioning on full blast in stop and go traffic. I will be hunting a proper AC Delco alternator and battery next week. No more parts store junk.
Tested my old alternator and it wasn't putting out any power at all.
Note for others: don't bother buying Oreilly alternators as it didn't last me 6 months. I wouldn't have bought one to begin with but the bearing in my GM original finally died after 140,000 miles last October/November.
Appreciate the comments!
Tested my old alternator and it wasn't putting out any power at all.
Note for others: don't bother buying Oreilly alternators as it didn't last me 6 months. I wouldn't have bought one to begin with but the bearing in my GM original finally died after 140,000 miles last October/November.
Appreciate the comments!