Originally Posted by
dom03
How do you test for drain, is this the correct way before I do it?
1. Put multimeter in 10A DC mode
2. remove negative cable lead off the battery terminal
3. touch one end of the multimeter probe to the negative cable lead
4. touch other end of the multimeter probe to the negative battery terminal
So ultimately your measuring the current running through the negative terminal on the battery between the vehicle and the battery for any drain? and if its above 50-60mA at or below your fine (since the computer uses some drain anyway when car is OFF)
And if you over this 50-60mA you may have something draining too much current when vehicle is OFF and thus draining your battery overnight?
You are right, this is how it's done.
I've spent 31 years in land mobile radio, the complaint that "Something is draining my battery" is quite common, but USUALLY the problem is the battery, not some device draining the battery.
The other problem, is equipment (sound systems, video systems, etc.) that are connected such that they are not really off or disconnected when they should be.
I have seen Ford Crown Vic Police cruisers with a factory drain of about 40 to 110 mA, with no explanation of the variation. Any drain of less than 100 mA is PROBABLY as good as you can get it - but remember, this number is WITHOUT ANY AFTERMARKET stuff connected!