SharkSkin

That's a lot -- 320 milliamps? it can't be .32 milliamps... lowest I've seen is about 40 mA.

Charley B

I'm probably doing this all wrong, but here is what it looks like. Do I have the meter set wrong?

Bill Ball

Hah, hah. Although the screen indicates -00.35 mA, I'm with Dave on this. Check the manual for the meter. 30mA is the lowest I have seen.

Be careful how you do this or you will blow the fuse in the meter, if it has one. You should have the battery post to battery cable bridged with another wire, apply the meter as you show, then pull the bridge wire. The prevents the initial surge that is seen when attaching the battery from going through the meter. It looks like the common lead you are using is max 400mA which is easy to exceed if a light happens to come on. Use the 10A lead.

SharkSkin

Hmmm... looks like it's reading .35mA all right. Switch the test lead to the 10A socket on the meter and switch the dial to 10A -- what does it read?

Also, the trick to this, especially on the later cars, is to keep use alligator clips or similar to connect the DMM without interrupting power. Something like:

1. Connect one meter lead to ground
2. Connect the other meter lead to the battery - terminal.
3. With the main ground strap connected, start the car, then shut it off.
4. With the meter leads connected, disconnect the battery ground lead.

The idea is that you always have a current path. Initially the current path is through the battery ground lead; you start the car and it energizes everything that's going to be energized.

Then, after you shut off the car, you disconnect the ground lead while maintaining an electrical path through the meter. Now all power is passing through the meter, and can be measured.

The problem is, if you disconnect the battery then connect the meter, you have interrupted power and certain devices that normally latch into an "on" state will not be "on" as they are normally when you park the car -- so you will not see them in the meter reading.

Clear as mud now?

Charley B

Not at all. that's very clear. I'll go do it now.

Charley B

OK, before I proceed, let me check this with you. With everything turned off and the ground strap disconnected, if I touch a jumper wire to the negative terminal and the other end to a chassis ground I get a pretty good spark. Should I proceed as outlined above?

Bill Ball

Yes, there will be an initial surge. Connect your meter, then pull the jumper. Door closed and all lights off, of course.

Charley B

Jumpered terminal to cable, started car, shut car off, all systems off, removed cable, attached leads and removed jumper. What does this tell us?

SharkSkin

That tells us you're doing it right.

A 2A drain is not enough to drain a healthy battery in an hour IMHO, but it's a starting point. What you need is to load test the battery -- any auto parts store ought to be able to do that for you.

Based solely on the info I see in this thread, I see two problems:

1. 2 A is way too much drain. You should be seeing ~1/40 of that much drain.
2. The battery should not die in an hour with 2A drain.

Car batteries are typically capable of storing 50 amp-hours or more of power. That means they can output 50 amps for an hour, theoretically. Close enough for this discussion.

So if you have a 50 amp-hour battery, 2 amps drain should take 25 hours to kill it. Your battery(again, based on info posted here so far) is acting like a 2 amp-hour battery.

Charley B

Interestingly, when the battery seemed to have drained in an hour or so it had included a 10 or 15 minute drive. I left the battery connected last night, reading 12.7v and when I got home today it was only down to 12.4v and the car started. When the car is running I'm getting 13.9v so it seems to be charging OK, at least when I check it as it's idling.

I'll get it load tested tomorrow. I did a hydrometer test a few days ago but it was inconclusive.

The PO installed remote door locks, remote start, after market amp. and stereo so I'll have fun running this down.

Thanks Guys.

Bill Ball

12.4 V is only ~75-80% charge (unless it was cold in the morning). So, it lost quite a bit overnight.

If the battery checks out OK, repeat your procedure and start pulling fuses. You need to do something so the meter will stay attached to the battery and you can read the meter while you fuss with the fuses. If the fuses don't reveal the circuit involved in the excess drain, then things get more interesting. 2 amps is a bunch.

WallyP

Check the battery positive terminal for added wires to the amp, etc., and try disconnecting only those first.

Also, I didn't notice anyone asking the standard first question - Do the interior lights work exactly as designed? On when a door or the hatch is opened, off when it is closed?

And I will second John's suggestion about the rear defog/defrost...

ew928

What Wally said.

Plus pull fuse for the radio to take stereo out of the loop.
And disable the aftermarket amps too.

Looked at the 2 overhead light sockets?
Those get very good at arcing to ground as the '+' spade is NOT insulated and only mm/cm from the chassis. (Great design VW/Porsche. Couldn't get any insulation sleeve on the spade, Porsche. Sigh)
Might want to play with the overhead lights after battery is disconnected so you don't blow the fuse.
(Why waste a good fuse)

the flyin' scotsman

2 amps is huge...........be very careful what your doing now. As Dave suggests secure the meter leads to the -ve batt post and cable. I'd start with the fuses associated with the aftermarket stuff and while pulling them record what current values you get. Leave the meter on the 10amp position until you get below 100ma then switch position and see what values you have.

Bill Ball

Good reminders from Wally, et al. Your interior lights are suspect based on what I saw the other night.