Vanagon-tom

Would this test work to test for battery drain?

Disconnected the negative on the battery, hook a test light to the negative post on the battery and the negative battery cable. Take out one fuse at a time to see if the test light gets brighter. If the light gets brighter, you know what electrical system is shorting to ground. Will this work?

To see if its the altornator not charging, disconnect the negative to the battery, if the vehicle dies, then the altornator is bad, is this safe on the altornator or is there a better way to test the alternator?

Thomas

bakertools

I am having a similar battery drain issue in my 2003 Jetta that just started. Did you ever figure out what was causing your trouble? I have a post going for my problem and the testing that I have done.

Easiest test for alternator is to test across the battery with it running and it should be reading above 12v and steady. probably up in the 14v range.

rogue13

hello the best way to test for a drain is diconnect the earth side of the battery connect the test light between the earth cable and the earth sid eon the battery now the test light will light up if you have a drain, now if you take each fuse out one by one if light does not go out replace that fuse untill light goes out. the only other way that you might have a drain is if you have an immobilizer fitted as some of them wont show up a drain the test light way good luck

rogue13

to test the alternator you need to get to the back of it and use a multi meter connected to the live side and the black wire on the multi meter to earth this should give you a reading that is right out of the alternator