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Discussion Starter · #1 · (Edited)
I'm having problems with my battery being drained by something in the car. Could possibly be stereo related. It also keeps blowing the fuse to the door lock & window switch. It really sucks. This all started happening after my accident. I'm still waiting for the car to be inspected, and I'd like to have everything working properly. Like everyone else, I'm low on cash, but could offer trade or work something out. Any help would be appreciated!





 

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Best way to diagnose this problem is this way:
Unhook the positive terminal from the battery.
Hook up an ammeter up in between the post of the battery and the now disconnected connector. Make sure you do NOT try to start the car or turn on the stereo, etc. This will overload most ammeters.
Take a baseline reading with everything disconnected. You should see under 50 milliamperes (mA). If you're significantly higher (75 milliamperes total) then it's time to figure out what the problem is.
The usual culprits are lights not shutting off in the cabin, trunk, glove box, etc.
Next, start pulling fuses one by one until you locate what's causing the draw. You can pull and replace one at a time until you figure out which one it is.
Aftermarket stereos, alarms, and turbo timers may cause an extra drain, so if you have those on their own circuits try to isolate them as well by removing power.
If it's a fuse, then you can simply look up what's connected to that fuse in a shop manual and figure out what's getting power from that circuit. It should be easy to trace down.

Good luck! It sounds like your problem may be related to your door lock or window switch sticking and overloading the fuse for some reason. Window switches are usually on circuit breakers, so I'd suspect the door locks first.
 

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Discussion Starter · #6 ·
Thanks for the tip! I'll have to purchase a meter. It seems like I had one, but I'm not sure where it is after the move. I love it when I can get things done on the car by myself. Sometimes I can't fix it on my own and it frustrates me. Being female is hard sometimes!
 

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No problem! You can buy a cheap multitool at any hardware store, just make sure you put the leads in the right ports (the ground usually doesn't move, the mA should be marked) and then turn the dial to mA.

Electrical work is easy once you've learned how simple circuits work, and what things you should be measuring.
 

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Discussion Starter · #10 ·
Thanks for everything! I'm going to try to self-diagnose the problem before taking it somewhere else. It still has not passed the state inspection to be re-titled & insured, so I can't drive it anywhere yet.
 

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Discussion Starter · #11 ·
I went and bought an amp meter. It's a bit more complex than I expected. What setting do I need to put it on? It has DCV with 5 selections, ACV with 2 selections, DCA with 4, Ohms (omega symbol) with 5, hFE, 10A, and an arrow connected to a plus sign. There's also a yellow dial with NPN and PNP. The directions don't go into a whole lot of detail.
 

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10A is the setting you need to worry about. If you want to post a zoomed in picture of the dail I'll MS paint you up definitions of everything. However, from what your saying you have AC, DC, Ohms, not sure on the hFE, amps, diode test, and the NPN and PNP are usually for transistors, so some sort of transistor testing.
 

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Not knowing that specific meter, it looks like you need to move the red lead to the top hole (bottom right hand corner) and then move the dial to 10 A (pointing right at the lead).

The most important thing is to not try to crank the car or turn on any high draw things (headlights, etc.) because you've only got 10 amps before the fuse in the meter blows.
 

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Discussion Starter · #15 ·
The instructions say that 10A is rarely used. The guy at the auto store said turn the knob to the 20 DCV. I'll figure it out.
 

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the DCV should be DC volts, the 10A is what you need. Also, make sure you do the measurement in series, and do not try to start anything or cut on lights or radio as said.
 

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He's right, most times you aren't trying to figure out amperage. But in this case you really are trying to figure out how much draw you have when your car is sitting in the off position.

I'm almost willing to wager that if you have a stereo amp in your car, it has been hooked up to a constant hot instead of a remote hot.
 

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Discussion Starter · #20 ·
Yeah, it was the radio. I pulled the radio fuse and saw the amps go waay down. I've left it out for 2 days now, and no battery drain. I haven't figured out the door switch problem, but it could be the switch itself. I was going to put another fuse in, but I'm sure it'll pop.
 
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