Battery Dead (Out of Ideas)

[savegoodautonfg]

I have a Powermaster 140 Amp Alternator which is about 4 months old. I just bought a new battery 2 weeks ago. My car sits for one day and the battery is dead the next day. Why could this be happening?

I just installed a new radio but i even had this type of problem with my other radio.

The reason for the bigger alternator is because i have 1 1000 watt amp and 1 600 watt 4 channel amp for my speakers and subs.

Any ideas to help me out a bit?

Just to add. when tried to start car electrical clicked on and as soon as i jump it for one second it will start no problem. no hesitation.

 

[savegoodautonfg]

my radar detector is on all the time even when the car is turned off. i have a escort 8500. i dont think this could be it.

 

[jrichker]

Typically it is something draining the battery. Small things like glove box or courtesy lights are often the culprits. If you have an aftermarket stereo or alarm system, it is also suspect.

The ideal method is to disconnect the positive terminal, and connect a Digital Multimeter (DVM) between the positive terminal on the battery and the positive cable. Set the DVM on a low current scale of 2-5 amps if it doesn't auto range. Watch the current draw, and then start pulling out fuses. When you see a sudden drop in the current, that circuit is the likely culprit. Note that the computer, radio & clock will draw less than 1/10 amp to keep the settings alive.

 

[savegoodautonfg]

Typically it is something draining the battery. Small things like glove box or courtesy lights are often the culprits. If you have an aftermarket stereo or alarm system, it is also suspect.

The ideal method is to disconnect the positive terminal, and connect a Digital Multimeter (DVM) between the positive terminal on the battery and the positive cable. Set the DVM on a low current scale of 2-5 amps if it doesn't auto range. Watch the current draw, and then start pulling out fuses. When you see a sudden drop in the current, that circuit is the likely culprit. Note that the computer, radio & clock will draw less than 1/10 amp to keep the settings alive.

thanks for the reply. one quetion is Set the DVM on a low current scale of 2-5 amps if it doesn't auto range??

Why would i want to set it on low scale volts. and also i leave it connected like you said to and then start pulling fuses and when the voltage drops lower thats the problem?

 

[89stangWhiz]

you always want it on the lowest scale possible so you can get the best reading.
If you have it set for 1000, and you were reading around 5 volts, how would you know if it dropped to 4.5, 5 would be the only thing on the readout.
By setting it lower, you see into the decimal places further.

 

[savegoodautonfg]

you always want it on the lowest scale possible so you can get the best reading.
If you have it set for 1000, and you were reading around 5 volts, how would you know if it dropped to 4.5, 5 would be the only thing on the readout.
By setting it lower, you see into the decimal places further.

thanks for the helpful reply man. so just do that and start pulling fuses and see when and if the voltage drops then that fuse is my problem?

 

[88Stang331]

I would check fuses and check for a short.

 

[jrichker]

The idea is that you use the current setting on your meter.

Current in an electical circuit is like volume in water. There will always be voltage present when the battery is connected to the elecrtical system. It's the current flow that sucks all the power out of the battery. Wheny ou pull the fuse that supplies the offending electrical item, the current draw drops off sharply. You will see the difference on the meter. Plan to disconnect the alternator power feed, but use extreme care. Shorting the alternator power feed to ground can make a nasty shower of sparks and damage electrical things. If the alternator has a bad diode, it will run down the battery.

 

[savegoodautonfg]

If the multimeter has a positive and negative how am i suppose "connect a Digital Multimeter (DVM) between the positive terminal on the battery and the positive cable."

 

[savegoodautonfg]

bump

 

[1993SSP]

Just pull off the cable, place the (-) of your meter on the positive terminal of the battery, place the (+) of the meter on the positive battery cable..........

 

[BullittAndy]

You're gonna love me if I'm right. If you have mirror lights in your sunvisors, check them. The velcro on the flap on mine was just loose enough to allow the light to come but not loose enough to allow me to see that the light was on.
I disconnected them and fixed the problem.

 

[superhuaman]

my radar detector is on all the time even when the car is turned off. i have a escort 8500. i dont think this could be it.

Come on dude, of course that's it...if not the whole problem then a good bit of it.

 

[savegoodautonfg]

It was the mirrors. superhuman ur the ****t... sorry so long to respond.

 

[ALMOST STOCK]

Man you're bring them back from the dead aren't you.

 

[Turkey Sammich]

I once had the check seat belt light fall down just a bit. When I was in the car, I could not see it was on. So thought nothing of it.

One night it was jacked up at the shop, the last guy out of the shop turned off all the lights and noticed a dim light still on. It was that damn check seat belt light

 

[Darkwriter77]

Check seat belt light? I thought that only came on with the ignition switched on...?

I had the constant-on mirror light problem, myself, for awhile until one night I got in my car and noticed a glow from above. I didn't have to disconnect it, though, I just put a piece of cardboard in between the flap and the button that shuts it off so that it'd push the shutoff button in when the flap was closed.