I'm pretty sure that it's my alarm. Is there any way to verify-short of charging it up and re-draining it-that my alarm is stealing up my juice?


it still works fine. I had just bought a new battery though and after a couple days of sitting, it would not crank (int. lights barely came on). only things connected to my + are the HIDs and the alarm. Ive disconnected everything to save the battery.


any help appreciated

 

You want to measure the "dark current," in layman's terms the amount of power that is being used when everything is supposedly turned off.


0. Get a digital multimeter, make sure it can measure current (Amps). Some meters will require you to have the test probes connected to different plugs in order to measure current (Amps).

1. Turn car off. Remove the key.
2. Turn off everything (lights, radio, etc...)
3. Disconnect a battery lead (does not matter which one)
4. Set your multimeter to read Amps or milli-Amps (use the highest scale, often 10A on most meters)
5. Put one lead on car battery and the other lead on battery cable. If you get a negative number, switch the leads.
6. Dark Current draw should be less than 50 milli-Amps according to the Mazda service manual. That's 0.050 Amps.

Assuming your Dark Current is more than 50 mA, here's how to find your draw.
7. Remove fuses, one at a time, keeping an eye on the Dark Current reading.
8. If you take out a fuse and the number changes a lot, you've found the problem. Check what is powered through that fuse circuit.
9. If you have any custom wiring that goes straight to the battery (gauges, alarms, stereo stuff) check that first, custom installs are often the culprit. You should really add a fuse to custom work, you can buy inline fuses at nearly any auto parts store).

Hope this helps,
-s-

 

aweeeesome info man, thanks!

 

scotty thats the best damn post i have ever read.