why dose my car battary go dead

christinaandisrael
0

Asked by christinaandisrael Mar 16, 2013 at 10:10 AM about the 2005 Cadillac STS V8

Question type: Maintenance & Repair

10 Answers

John Sturman
1,635

could be a duff 1 or the alternator could be drawing charge back through a duff zenner diode

3 out of 3 people think this is helpful.
tenspeed
68,335

A diode by definition is a device that allows current to flow in one direction. A Zener diode is a diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage. Zener dfiodes are not used in automotive alternators. --- The battery could be losing voltage due to a parasitic drain. Here's a video explaining it and how to find it. https://www.youtube.com/watch?v=KF1gijj03_0

19 out of 19 people think this is helpful.
tennisshoes
40,315

A lot of things can kill a battery. As I don't have the exact year of the car I'm going to take give you a few things to check. First of all have you battery tested to make sure it is up to the task of holding the parasitic loads this car has. if it checks good then here is a list of what to check next. Glove box light, make sure it turns off, if in doubt remove the lamp, trunk light same thing, underhood light also, interior lights and there is a lot of them, vanity mirror lights, stuck brake lights switch. If all of the lighting check out then you will have to check for excessive draw on the battery, like alternator diodes bad, stuck relays, alarm system. This can get involved. Good Luck

1 out of 1 people think this is helpful.
username
105

One of the most common things I see is one of the lights under the rear view mirror gets turned on when adjusting the mirror and this drains the battery.Check those first. Next disconnect the alternator wiring and check for an excessive drain.....do not confuse the small drain needed for "on star" and other computer related items.Generally a 12 volt test light put between the positive battery post and the positive battery cable with the cable disconnected from the battery should glow dim (normal)but not brightly. remove fuses one at a time until the test light glows dimly. (keep the doors closed and disconnect the under hood light if needed) Dim light OK Bright light DRAIN Disconnect the battery completely for a day or two,reconnect and see if it is still charged. Dead battery.......time for a replacement. Good battery......keep looking for a drain!

6 out of 6 people think this is helpful.
tenspeed
68,335

The Cadillac should have the battery saver function that will shut all circuits down after twenty minutes if a light was left on. It will not shut off the cigarette lighter circuits so don't leave anything plugged in with the engine off.

2 out of 2 people think this is helpful.
tenspeed
68,335

It could be an internal short in the battery. Try disconnecting the negative battery cable at night and see if the battery is flat in the morning.

Js08016
32,545

How often do you drive the car? If it sits for extended periods of time the computers in the car will kill the battery. Disconnect the negative (-) battery cable if you plan on not using the car for more than about a week. HTH. -Jim

5 out of 5 people think this is helpful.
dmarrujo
40

My car will not start. I'm going to see if it's my battery. I use my car once to twice a week. I do leave my cigarette tray open all the time after disconnecting my phone charger.

1 out of 1 people think this is helpful.
dmarrujo
40

Nope..its not my battery..

1 out of 1 people think this is helpful.
pussyy
0

My 07sts Cadillac keeping cutting off when I come to a stop

Your Answer

Add photo

Related Questions

STS
Looking for a Used STS in your area?
CarGurus has 1,355 nationwide STS listings starting at $3,500.
ZIP:

Search Cadillac STS Questions

Cadillac STS Experts

#1 tenspeed
tenspeed
Reputation 240
#2 username
username
Reputation 60
#2 Tom Demyan
Tom Demyan
Reputation 60
View All

Related Models For Sale

Used Cadillac CTS"
259 Great Deals out of 12,024 listings starting at $1,995
Used Cadillac DTS"
74 Great Deals out of 1,786 listings starting at $2,990
Used Cadillac SRX"
302 Great Deals out of 18,699 listings starting at $1,900
Used Cadillac Seville"
7 Great Deals out of 482 listings starting at $1,400
Used Cadillac STS-V"
27 listings starting at $12,995
Used Chrysler 300"
378 Great Deals out of 22,722 listings starting at $2,990
Used Cadillac CTS-V"
5 Great Deals out of 219 listings starting at $10,990
Used Dodge Charger"
460 Great Deals out of 28,111 listings starting at $3,200
Used Cadillac DeVille"
38 Great Deals out of 2,280 listings starting at $999
Used Chevrolet Impala"
1,496 Great Deals out of 55,955 listings starting at $1,399
Used Cadillac Escalade"
128 Great Deals out of 6,003 listings starting at $3,995
Used BMW 7 Series"
89 Great Deals out of 5,190 listings starting at $3,995
Used Ford Mustang"
651 Great Deals out of 33,489 listings starting at $1,595

Used Cars For Sale

2011 Cadillac STS For Sale
8 Great Deals out of 113 listings starting at $13,895
2010 Cadillac STS For Sale
48 listings starting at $10,400
2009 Cadillac STS For Sale
5 Great Deals out of 142 listings starting at $10,500
2008 Cadillac STS For Sale
7 Great Deals out of 217 listings starting at $7,977
2007 Cadillac STS For Sale
7 Great Deals out of 205 listings starting at $5,995