Battery drain .....f#$%^&* !!!!

[Firestorm91tt]

I have a 93 RT TT (formerly HellBringer's and WAYNECAR) and have had an issue that has had me scratching my head for sometime. The car seems to go dead after sitting a day or so. I have replaced the battery with a brand new one, that was tested / load tested from where I bought it and it will hold a charge outside the car for days on end. However, as soon as you install her...shes starts dropping in voltage metered at the posts via multimeter.

At times, I will start with 12.81v and after a few hours it will drop down to 12.60v and continue to plummet. You can literally watch the multimeter dither between current voltage by 0.01v, until it drops a bit and continues to dither on southward (again by 0.01v at a time).

Hopefully I wont jump back and forth too much to add to the confusion, but I am really stumped.

Now I went to do a parasitic draw test on the car (which I think I did correctly) and didn't see any obvious signs of draw. I placed the multimeter in series with the negative ground cable and the negative battery post (meter dial set to 20/10A measuring under DC mA and connected the leads to the appropriate spots on the meter {COM / 10A } and saw a draw of 0.04. Is the 0.04 something to be concerned with?

With a steady reading of 0.04, I began pulling each fuse and did not see a significant drop...it stayed for the most part at 0.04 but would dither to 0.03.

With that portion complete, I though maybe the alternator was causing the drain since I read that it could feed back power from the battery. I took the meter out of series and just stated checking voltage again. Within that time I went down appox. 0.05 v which was probably half an hour or so. Again, the voltage would dither back and forth 0.01v at a time and continue south.

I pulled both the harness clip and power wire to the alternator free and still see the meter dithering south, so I guess I could say the alternator is not my issue and is good (this too was tested at time of battery load testing).

Needless to say, I will bet if I leave the car as is (everything hooked up as it should be) she will be deader than a door nail by this time tomorrow.

The car does have an aftermarket stereo and amps, however I have it defeated by pulling the Stinger fuse off the firewall where its mounted.

Can anyone offer some insight on where to turn to next?

[anyonebutme]

start pulling relays. Did you pull any of the fuses under the hood or just inside.

[Firestorm91tt]

I pulled every fuse in the engine bay and by drivers foot rest. I was unable to get the relays in the engine bay to budge (without pulling top portion off....relay remain seated). Need to get a small pick screwdriver or hook to wrestle em out.

[anyonebutme]

a trick is to just pull the cap of the relay off, then you can manually engage or disengage it.

[Firestorm91tt]

Hmmmm...need to do some studying up on that then...would hate to jump in feet first and catch something on fire....hahahahhaha

[sublime_whatigo]

The "0.04" is not much to be concerned with assuming I'm understanding you correctly. I think ideal is .01 (10mA) and the upper limit is .03 for general cars, .04 should last like 3-4 weeks before it won't start a good battery.

Do me a favor and open your door while the meter is connected, generally speaking the interior lamps are like 2 amps, so you would read 2.04 if that were the case.

[Jimvr4]

Speaking of doors, the sensors might be intermittent and shorting to ground causing the current draw. You could disconnect them for a few days as a test.

[Firestorm91tt]

Good evening.....

I hooked the multimeter back up in series and still had the 0.04 reading. I went over to the passengers side door and popped it open. Reading on meter jumped to 0.42.

dooropen.jpg

The "0.04" is not much to be concerned with assuming I'm understanding you correctly. I think ideal is .01 (10mA) and the upper limit is .03 for general cars, .04 should last like 3-4 weeks before it won't start a good battery.

Do me a favor and open your door while the meter is connected, generally speaking the interior lamps are like 2 amps, so you would read 2.04 if that were the case.

[Firestorm91tt]

Also...on a side note I wanted to go back and test the battery. As I mentioned it was load tested at the parts store and checked out ok. Over the past few days, I left the battery disconnected (both positive/negative terminals). The charge started off at 12.98 and slowly dropped down to 12.61 where its been sitting for a couple days. I figure what I lost was just surface charge. I am leaning towards the battery being good.

I hooked the battery back up (both terminals) and started monitoring voltage again. It would start at 12.61 and dither 0.01v (12.61 >12.60>12.61) etc, until it would fall down that one 0.01v and continue to dither (12.60 > 12.59 > 12.60) etc.

Im really stumped. I figured a draw as significant as this would show up easier when meter is/was hooked up in series.

[box]

40mA is excessive current draw, however it definitely shouldn't cause the battery to go flat over a day.

Try to get your hands on a known good battery to sit in there and try for a few days, I bet that's where the issue is (even though it's theoretically OK). I have seen batteries which would do this exact thing, they load test fine and hold their voltage on the bench, yet when they're fitted to a car they drain to the point where they don't start.

Out of curiosity, is the battery clamped down?