Disconnect the alternator and check it again.

Kevin

Disconnect the alternator and check it again.

Kevin

Feel the alt.& see if its warm,alts.can draw on a battery when there's an internal fault.

Ensure you have everything turned off, map lights etc. if you have a newer vehicle with an ECM etc. you will need to let it "time out" or "go to sleep" for testing the draw, this includes ensuring your door is closed (no draw from a dome light, under hood light etc.)
Disconnect the negative battery terminal, now make that connection by hooking an ammeter between the batteries negative terminal and the disconnected battery cable end.
This will tell you the draw.
You can pull fuses and disconnect things until you find the suspect circuit. Then you will know if you have an excessive draw.

when disconnecting the neg.batt. terminal to connect a DVOM you have to hold the leeds against the terminals if it disconnects & goes open the vehi.wakes up again {on newer cars} & you have to wait for it to go to sleep again.

what does the battery voltage measure just sitting there?
I ran into the same question and then remembered that a battery going bad isn't going to have a high resting voltage like a new one.
the battery was 12.5 volts. vs the normal 13.5 you would expect.
I even ran it on a charger for a while and it came back down to the 12.5 volts after just sitting.

I've had a lot of bad batteries the last few years. Some even loose their charge being disconnected. Others being connected even the smallest load like what the clock memory draws is enough to make a difference even if the battery holds a charge when it's disconnected.

If you have the ignition switch light make sure that goes off. That stopped timing out on a friends car. Unless there's something aftermarket the only real stuff on an M to cause drains is problems with the radio, ignition module, or a light that's not going out. Or the alternator thing that was mentioned altho I've never personally seen that problem.

I've had a lot of bad batteries the last few years. Some even loose their charge being disconnected. Others being connected even the smallest load like what the clock memory draws is enough to make a difference even if the battery holds a charge when it's disconnected.

If you have the ignition switch light make sure that goes off. That stopped timing out on a friends car. Unless there's something aftermarket the only real stuff on an M to cause drains is problems with the radio, ignition module, or a light that's not going out. Or the alternator thing that was mentioned altho I've never personally seen that problem.

Gonna add rear window defrost to list.

Also, forgive me,but I've noticed in a lot of your post you feel to follow diplomat with AHB or AFB why is that?

Been wondering if I have a parasitic draw or battery going bad in my Diplomat AHB. Battery runs down way to quick after sitting just a week to ten days in the garage. It's a big Interstate just over three years old. I finally got around to pulling negative cable and checking with multi-meter, and shows 60 milliamps. I thought this was kind of a lot, but wasn't sure, so I pulled every single fuse, and NO change.

Battery going bad? Am I missing something? I pulled every fuse. Is 60 Ma unusual necessarily?

Thanks.

Larry

Yessir and that will drain a good battery. If pulling the fues didn't identify the culprit then it is something likely connected all the time, IE: alternator as suggested, starter, starter relay (doubtful), ignition switch or wiring in the column. Has to be something that is non fused (box wise) and connected to the battery when the switch is off. I had one that drove us nuts for a bit, it was the clock motor that wound the spring. The clock didn't work so I didn't think to looks at it. However the points that open when the spring is wound were stuck shut thereby energizing the clock motor 24/7. Can't remeber the draw but it was 30ma + I think, Happy hunting and do keep up posted )

If you have an aftermarket voltage gauge installed, it could be that as well. I had one it my Powerwagon, that would discharge the battery enough in a week, it wouldn't turn over. Not sure why a gauge would do that, but it did.