I am measuring over 0.5 Amps with everything off. When I leave the trunk light on I have about 1.2 Amps.

I think I may have a short somewhere, my battery won't hold charge and it is about 3 months old.

Alternator has been tested and works.

Thanks.

 

It would help to kniow what year and model car. Idle current should be around 60 milliamps. On the cars with a CAN that should be after 15 minutes or so. I had a problem similar to yours with my 2000 and it was the old analog phone.

 

If you have a tracking unit, these have a battery that charges from your battery, normally installed in the front wheel arch behind the cover, if you no longer use tracking or if the previous owner had it installed for insurance purposes, remove the unit of replace its battery.

Had a similar problem with my Camry 2.4Gli but the merc battery is huge by comparison. Tossed the tracking unit and now the battery holds its charge.

A tip from the guy that replaced my battery said, if you do only short trips to work or wherever, you should charge the battery once a week with a trickle charge, it takes ±20km (13m) trip to bring it back to a full charge assuming your alternator is working efficiently.

 

This is for my 99 C280 Sport:

So after debugging this a bit more, I came full circle to the re-manufactured Interstate battery I had replaced in March of this year. I've now gone to a new one and for the last five days it seems to be starting without issue.

It appears the 500 milli-Amps on my car is acceptable.