: Charging System Diagnosis...



mstrjon32
06-20-13, 02:10 PM
Here's the facts:


New battery 6 months ago.
Car hesitates to start occasionally, sometimes I hear one or two clicks before it turns over.
Had the key in with the radio on for about 2 minutes and saw a "Low Battery Voltage" message. It was under 10.5 when I checked it.
The voltage fluctuates a lot while driving, and is in the 10-12 range. I feel like it should be 14+.
I haven't been driving the car much--but at least once a week.
Earlier this week it was really hot, and it flashed a "Service Steering System" message, and then immediately went back to "Stability System Ready".


Given that I just put a new battery in recently, and that the system voltage is so low when the car is running, I feel like the alternator might be on its way out, but I suppose it could be a defective battery, too. Wanted to get some opinions before I start poking at it more...

heavymetals
06-20-13, 02:18 PM
I would check the ground on the engine above the starter.

I just ordered a high output replacement alternator (240 watt) that isn't cheap.

Sounds like your alternator is going south.

JFensty
06-20-13, 02:57 PM
I had a similar issue and it was a loose wire on the back of the alternator. Cleaned and tightened the connection and no problem for almost a year.

P-Funk
06-20-13, 05:11 PM
May or may not be what you are experiencing, but my car doesn't like to go very long without being started. It has a drain on the battery coming from somewhere and if I leave it for more than a few days it will basically kill the battery. I went through several batteries after leaving it in the garage for a week or so each time. Several years ago I bought a battery tender and plug it in when I know that I won't be driving it for several days and haven't had any battery issues since.

darkman
06-20-13, 08:01 PM
See attached.

odla
06-21-13, 01:12 PM
I would say it is the battery again. Put a better battery in. I had the same but my battery was two years old. South Florida heat. I just put a pc1200m in and no problems now. I too only drove the car about once a week and it was only like ten miles.

heavymetals you mean amp? Also where and how much if you don't mind me asking? You can pm me if you like. Thanks

heavymetals
06-21-13, 01:34 PM
"heavymetals you mean amp? Also where and how much if you don't mind me asking?"

http://fastlanepartssupply.com/shop/04-05/04-05-06-07-cadillac-cts-cts-v-240-amp-alternator/

odla
06-22-13, 12:43 AM
Thanks.

isis
06-24-13, 05:06 PM
Make sure your interior light dimmer (by the sunroof switch) isn't on full-bright. It can drain the battery while it sits. I had it there for almost a year before it started causing problems. Pull it back to around 3/4 bright and see if that helps. I got intermittent airbag warnings and random dead batteries for a week or two till I just moved the switch. There's a tsb to direct the replacement but unless you love spending money and cant stand the dim dash on cloudy days you just need to pull the dimmer back.

jeph054
06-24-13, 05:31 PM
Here's the facts:


New battery 6 months ago.
Car hesitates to start occasionally, sometimes I hear one or two clicks before it turns over.
Had the key in with the radio on for about 2 minutes and saw a "Low Battery Voltage" message. It was under 10.5 when I checked it.
The voltage fluctuates a lot while driving, and is in the 10-12 range. I feel like it should be 14+.
I haven't been driving the car much--but at least once a week.
Earlier this week it was really hot, and it flashed a "Service Steering System" message, and then immediately went back to "Stability System Ready".


Given that I just put a new battery in recently, and that the system voltage is so low when the car is running, I feel like the alternator might be on its way out, but I suppose it could be a defective battery, too. Wanted to get some opinions before I start poking at it more...

Mstrjon:
Let me start off by saying I have been a Interstate Battery Distributor for over 15 years so I have expertise in this area. Couple of things...:

1. You can easily determine what the Alt is doing by putting a voltmeter on the terminal ends both while the engine is running and without. should be 13.8-14.8DCV that will give you a base line on what the Alt is doing.
2a. To determine if you have a Key-off drain ( battery draining with the key out of the ignition) take a reading with the volt meter after charging. A fully charged battery is 12.66DCV or higher. Record that reading and wait a few days and take another reading. If the voltage is dramtically lower (12.4DCV or lower) you could have a drain. BUT...
2b. The battery may simply be bad. I know you just bought it the battery but that DOES NOT mean it is new. If you bought it from a Mass retailer then the battery you bought could be several years old. They DO NOT have any kind of rotaion or battery maintenece in place at these stores. Batteries are only doing 1 of 2 things...either charging or dis-charging. So if a battery sits on a self for a long time, damage is occuring internaly. To make matters worse the battery group size of our cars is a group 101 which is not very popular so the likelyhood of it sitting on a self for a while is VERY high.

The battery could very well have a bad cell in it. This would explain the 10ish DCV. Each cell is 2.2 DCV so in a 12DCV battery if one cell goes bad....there is your 10DCV. There is a range for this voltage but you get my drift.
If the battery is not sealed (not a gell or AGM battery) pop the caps off and go to your local parts house and buy a hydrometer. they are cheap. This will check the specific gravity of each cell. If any one cell varies more than 50 points or 1 floaty ball then you have a bad cell.

If you have to buy or exchange your battery, look for the date code. It should have a letter and a number indicating the month and year of the battery ie. A3 is January of 2013. A=Jan,B=Feb.,C=March...etc. You should not accept anything that is older than 3 months.

Hope this helps. If you have any questions, PM me..

heavymetals
07-09-13, 03:04 PM
Here is an update and a kinda interesting story.

I have been waiting for the alternator and I got a call from the vendor.

After a short conversation/explanation the bottom line is that the alternator I am getting is a rebuilt OEM with the guts replaced.

The reason being the housing that they provide just isn't gonna fit the V.

I really appreciated finding that out (I remembered someone else ran into that brick wall) and the diligence of the vendor to make sure I knew what I was getting and why it was gonna look like the OEM.

The vendor told me he ran into this with his buddies car and that is how he knew.

Whatever, I am just glad I didn't have my stuff apart and then found out it wasn't gonna fit.

odla
07-10-13, 10:36 PM
good to know.

mstrjon32
07-11-13, 01:58 PM
I haven't started the car in 2 weeks. I'll probably get to checking it out sometime early next week. Will report back...

mstrjon32
07-23-13, 02:45 PM
Finally took a look at the car today. Took the battery out and cleaned the terminals, cleaned the ground on the passenger side on the fender near the hood strut, looked pretty dirty. Tried to find the ground on the back of the engine but couldn't, and the engine was super hot so I didn't try too hard. Looked at the connections on the starter and alternator, looked good, but tried to get the connections off and again it was super hot and I didn't feel like waiting around.

Anyway, finally, I put the battery on a SnapOn MicroVat tester. Failed. So, tomorrow I'll try and bring it back to the store and exchange it for another one. If I can get a better brand of battery for the exchange, I will...