So I checked out mA as suggested but was frustrated with .002 readings on all
fuse circuits. So before I narrowed what I was not doing correctly and having to amp clamp,
I read volts from the battery to try and isolate the ign switch.
Battery full charge, 13.09 volts, battery cables not connected.
3 days latter 12.89 volts.
Connected battery cables and disconnected ign switch harness.
Next day AM 12.2 volts
2 days latter AM 11.86 volts
Same day PM 11.67 volts
Connected ign switch harness
Next morning 11.31 volts
2 days latter 8.16 volts
Now charging battery.
guess a new switch is to be ordered.
Any help on confirming and direction before doing an amp test on all those God Damn circuits will be appreciated.
Bob V
Last edited by 1986series6; 09-22-2018 at 06:52 AM.
The results are consistent with either battery drain - or - just a battery that has reached the end of its life. At a terminal voltage of around 8 Volts the battery is being permanently damaged very quickly - if it's been at 8V for any length of time it is dead as a dodo.
Batteries are notoriously difficult to measure to ascertain if they can hold a charge - and with those readings I think I would start with a new, fully charged battery as a starting point, you cannot measure battery drain with a bad battery. I would then do an actual closed-current battery drain test:
https://www.meeknet.co.uk/E38/E38_Battery_Drain.htm
You can used a DC current clamp on the negative lead - the latest ones work pretty well as long as they are pre-calibrated (zero the meter when the clamp is next to, but not around the negative lead).
Last edited by Timm; 09-22-2018 at 04:30 PM.
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Timm,
Brand new AGM battery. Was fully charged @ 13.09 volts
This is the amp clamp ( https://pdimeters.com/docs/pdf/manuals/CA-60.pdf )
I'll use an inline fuse holder with spade connectors to check mA on all circuits
and I'll follow your sleep instructions. I hope I find high mA on a circuit to fix this PITA.
Thanks Timm
No need to remove fuses - and you mustn't remove them as this resets the 16-minute timer and removes evidence. Instead, use this method:
http://www.meeknet.co.uk/E64/Fuse%20...20Readings.pdf
What actually is the current demand after 16 minutes?
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
My BMW Repair YouTube Channel
My Current 840ci Sport Individual
My Current 650ci Sport Individual
My E31 Repair and Information Website
My E38 Repair and Information Website
My E63/E64 Repair and Information Website
Chase - Heroes to a generation
OK thanks for the heads up
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