QuestionWhen I ititially connect the battery, the draw is about 1.3amps for about 5-10 minutes and then it drops to 300 ma.
I have removed every fuse and relay and the major part of the 300 ma is thu a 10a "cluster" fuse....which disables the inst panel,radio,etc.
Can you suggest where to look next?
AnswerHi John, When I went to school and they taught us about battery drains the procedure was to make sure the key was out of the ignition lock cylinder...this is especially important on newer cars that keep the BCM awake because it knows when a key is still there...remove the negative battery cable and install an ampmeter between the cable and the battery or inductive amp clamp around all the negative cables and with the doors shut and underhood light off read the meter. After 30 minuits all the computors should have gone to sleep/powered down and the amp draw should be less than 20mA. Depending on the vehicle 7mA draw is normal.
Looks like you have gotten past that part because you have determined what fuse causes the draw to go to a normal range. The thing I like to do is remove the fuse for the interrior lights first and if the draw is still there leave it out so the lights can't be on to affect the reading.
Now that you know that fuse is the problem you will need to reinstall the fuse and start unplugging things that the fuse provides power to until the draw does down again. That part could be the problem of your draw. An exception would be like if the ignition key was causeing the BCM to remain awake because it was in the lock cylinder, unplugging the BCM would make the draw go away but replaceing the BCM wouldn't fix the problem because something is telling it to remain on. Hope that makes sense.
I would look at the wireing diagram or what the fuse sends power to and start disconnecting the easiest first and work to the hardest to get at while watching the meter to drop. Let me know the year and model of your vehicle if you need more help. Bill
