u/XandertheWriter

Hello all! Foreword: I think that an alternator diode broke, and the alternator is creating a large amperage parasitic draw, or there's a short somewhere.

'96 ZJ 4.0l is experiencing some pretty significant draw when it's off (greater than 20amp). At this point, it could also be the battery (bought it new 2.5months ago when car was purchased), as I left for 10 days and came back to a battery reading 6.5v. It is failing to hold 12.2v. I have installed a kill switch on negative terminal as temporary band-aid.

My

When checking for parasitic draw (by removing negative terminal, using multimeter at highest amp setting to connect between negative cable and negative terminal) there is a small arc between multimeter probe and negative terminal, which is now confirmed as more than 20a as this fuse and setting were rated for 20a.

Is this indicative of a short somewhere, or is this some easily avoided problem I'm unaware of? Is there some "startup inrush current" that happens if battery is connected? If so, how do I avoid it or test for parasitic draw some other way?

Thank you! I can provide pictures if requested

Edit: all physical knobs in OFF position, key out, doors closed (hood open) for 30 minutes, no lights on, etc.

Hello all! Foreword: I think that an alternator diode broke, and the alternator is creating a large amperage parasitic draw, or there's a short somewhere.

'96 ZJ 4.0l is experiencing some pretty significant draw when it's off (greater than 20amp). At this point, it could also be the battery (bought it new 2.5months ago when car was purchased), as I left for 10 days and came back to a battery reading 6.5v. It is failing to hold 12.2v. I have installed a kill switch on negative terminal as temporary band-aid.

My

When checking for parasitic draw (by removing negative terminal, using multimeter at highest amp setting to connect between negative cable and negative terminal) there is a small arc between multimeter probe and negative terminal, which is now confirmed as more than 20a as this fuse and setting were rated for 20a.

Is this indicative of a short somewhere, or is this some easily avoided problem I'm unaware of? Is there some "startup inrush current" that happens if battery is connected? If so, how do I avoid it or test for parasitic draw some other way?

Thank you! I can provide pictures if requested

Edit: all physical knobs in OFF position, key out, doors closed (hood open) for 30 minutes, no lights on, etc. when fuses are blowing