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2009 CTS4 2007 STS
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Discussion Starter #1
Could anyone tell me what is the correct voltage 0n a 97 STS. Last night had to get a boost because my battery just all of a sudden died on me. For the last couple of days I've had the sentinel lights set on max so my wife can have enough time to get in the house but the car was cranking fine. Before the jump the voltage was around 8 now it never gets past 13.8 and goes as low as 13 while i'm driving the car. Also when I cut the car off now the radio goes off and comes back on and all of the info on the DIC is reset. The car cranks fine but that makes me think there is a shortage since I boosted the car. BTW all cables are tight and free of corosion.
 

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1989 Sedan DeVille is now just a fond memory ....
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You've already checked the cables, that's good. Sometimes a boost can damage the alternator, it's not common but not impossible either. If the battery is low the system should get up to around 14-15 volts to recharge. If you have a battery charger I would suggest giving the battery a full charge and then have the charging system checked. A good service station can check it for you for $20 or less.

It's also possible that your battery is failing. I believe there is no such thing as a maintenance free battery. I always carefully pry off the caps to the cells and add distilled water to any that are low.

One last thought, be sure to double check the connections of the ground cables, the one on the battery to block and the one on the alternator.
 

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2009 CTS4 2007 STS
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298 Posts
Discussion Starter #3
Thanks Kev the battery is a side post and the last time I looked at it I don't think it is a way to get in it. I'll check it in the morning oh yeah I just replaced the alternator about a month ago because the bearings had went bad
 

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White Diamond '03 DHS (with DTS floor shift)
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electronics is not my strong point but I don't think you should ever see 8 volts. I think that is too low. If I recall correctly it should read close to 12 before cranking and about 14 when running. That said I am pretty sure the running voltage will vary by load and tempurature. My '97 Deville would run mid 14's in winter. Now I see my '02 SLS running mid 15's :eek:. Thats at night with lights, heat & radio.
 

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1989 Sedan DeVille is now just a fond memory ....
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I believe you are right Ranger. ej2000n, i hope this is not the case but as I said, sometimes getting a jump start can damage the alternator. The circuitry is much smaller than it used to be and can easily be overcome if it is subjected to a surge of juice as sometimes happens when the system is jumped.

It's also risky to try and recharge the battery with the alternator while driving if it is low. That has been known to overwork the alternator and burn it out. If your battery is weak or going bad it can cause the alternator to fail as well due to overloading.
 

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2009 CTS4 2007 STS
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298 Posts
Discussion Starter #6
thanks guys I'll just wait till Monday and get it checked. I have no choice but to drive the car with it being X-mas and everything. I've been watching the voltage while I drive and sometimes it will stay right at 13.2 no matter how fast I go. then it will go back to around 13.6-13.7. also when i start the car everything is reset as if i disconnected the battery. The DIC is always reset and sometimes I might have to reprogram the radio. I hope it is just the battery but would that cause those problems and the entire system is protected by fuses correct? :hmm:
 

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2004 Escalade, 07 Road King, 08 Challenger SRT8
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I'd be very very suspicious of a bad battery...........

I have had a couple batteries that didn't seem to want to take a charge, either. Some similar symptoms. Low voltage while running, for example.

14.2 would be the theoretical voltage while running, so, 14 or 15 is good. 13 point something is low... The car resetting everything makes me think the battery is practically dead. Or has Kev rightly pointed out, bad connection, bad wire, bad something, loose connection at the post, that kind of thing....I've had that exact effect from loose wires at the posts, loose grounds....

I'm unclear from your post if you now have to jump it every time, or is it starting on it's own now??? If it starts, is it weak, anemic, barely turns over?? Or does it fire up with authority??

I'm still highly suspicious of the battery. Batteries are funny things.... they crap out without warning sometimes. Get a new battery ASAP, before you get stranded somewhere.
 

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Cadillac Technician
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Open circuit voltage on a lead-acid 6 cell battery should be 12.6 volts when fully charged. Each cell is designed to store and generate 2.1 volts (approximately)

Charging system output can vary but should always be within the 13-15V range. Lower voltage would indicate a possible battery or charging system fault, higher voltage would indicate an overcharge condition from your Generator (alternator).
If the voltage was 8, it's quite likely that you have a bad cell or two. Have the battery tested. Most of the batteries you'll find are what we refer to as "side terminal". The "post" is the thing that sticks up out of the top on the old style batteries. Side terminal batteries are prone to acid leakage, mostly found from the positive terminal. If it's leaking around your battery please use precautions, that is acid and quite corrosive to metal and human flesh. It doesn't feel good when you get it in your eyes either... I know all about that.

My guess would be that you either have an electrical drain or a bad battery. If you haven't made many other changes lately, like adding radios or other electrical loads, it's probably just a bad battery.

HTH
 

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2009 CTS4 2007 STS
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Discussion Starter #9
thanks for the input guys. I only had to jump it that one time. when i started the car today the volatge stayed on 14.3 for a while and it was around 12 before the engine started. everything worked fine today no resetting or nothing. I'm still going to get it checked, this car does that 2 me everytime i have to take it to the shop, kinda like a kid whose sick untill its time to take the medicine. Either way it's going the thought of being without a vehicle 1 day before Christmas was to much for nerves to bear. again thanks for the input
 

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You probably have a bad cell in the battery. My guess is the car sat for a little bit longer period than it normally does before you noticed this problem.
On a '97 you should have a 78 series battery in there.
 

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2004 Escalade, 07 Road King, 08 Challenger SRT8
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Ewill3rd makes a great point about side terminal batteries, great point. They can leak from the post. As a former C5 Corvette owner, I can tell you we were terrified of that leakage, because it tended to leak all over the electricals that ran directly beneath the battery, which was rather disastrous....

I also agree with him that it is probably a bad battery....

Corvette people loved the Optima batteries, because they are (I am told) full of like a jelly type substance, instead of the watery acid type fluid, and I have not heard of an Optima battery leaking from the posts. They cost a little more.... There's a store here called Farm & Fleet that sells them as cheap as anyone.

Also, I should clarify my earlier post: 14.2 is with the car RUNNING. Sorry for the confusion, my bad. Ewill3rd is also exactly correct, the voltage in each cell of a perfect battery is 2.12 volts. Times 6 should give you 12.7 volts on a digital VOM. So, car NOT running, 12.x would be good.

Also, it should always be pointed out, and again Ewill3rd is right, acid is very bad. Use every precaution. After you spend 15 minutes at an eye wash station rinsing your eyes, it gets a lot easier to remember to put on your goggles....:eek:
 

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I know what you mean on the C5's, I used to clean a lot of those up.
That is why they went to the AGM batteries, no acid!
Too bad they took them all away.
The electrical stuff usually held up pretty well, except for a couple of grounds and the vacuum hoses that went to the HVAC system and made the air blow out of the defroster all the time. Man that sucks to fix on those cars.

Thanks for your comments.
;)
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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Having a similar problem myself, battery is at 11.8v and tested good at vatozone, 11.8 at the connections of the cables, not enough current to start. Stuck driving the 75 (It's HORRIBLE I know :p ) Likely a connection or ground in my case...
 
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