Untraceable parasitic current draw

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Untraceable parasitic current draw

Post by Swanny » Mon Jun 13, 2016 7:47 pm

Hi all,

So my Turbo's been cooped up in the garage for the winter and I decided to take it out for a spin yesterday after re-insuring it, but it wouldn't start - completely dead battery.

I've been starting it and running the engine for 15 mins every few weeks and it's always started first time. I jumped it in the end and it started fine. I charged the battery overnight and it started fine today so I decided to check for parasitic current draws. After 10-15 secs the current drops to 0.14A with nothing running/on. I've never checked this on a car before so I was wondering if anyone knew what it should be; I read on another thread that it can get as low as 0.03A.

I've been through all the fuses that I can find disconnecting one by one and there was no change to the current reading. I can only find fuses one the 3 relays in the engine compartment and the one's in the fuse box under the steering column. Any similar experiences? The only the thing I have changed recently was the ignition coil a few weeks ago but I isolated this and nothing changed. As always I appreciate any advice anyone can offer. Nice to take the old girl for a spin, put a big smile on my face, even got a thumbs up off some young lads :D Cheers.

480 Turbo S/R 'Matilda' - '89 red - Norfolk

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Re: Untraceable parasitic current draw

Post by brinkie » Tue Jun 14, 2016 10:55 am

Buy one of these:
http://www.ebay.co.uk/itm/Battery-Isola ... 1732970085
and disconnect the battery after use. Have been using a kill switch for years.

Can be found a wee bit cheaper if you are willing to wait 2-3 weeks for the mail from China to arrive.
http://www.ebay.com/itm/Universal-Batte ... 2010703962

Parasitic currents can be a real pain to find, most of the time the CEM is the culprit as this one is microprocessor powered and should stay on all the time for the alarm to function; if the processor doesn't power down properly it will still draw noticeable current, and the LED flasher draws a couple of milliamps of course. And still, I can remember that after three weeks the battery of an extremely basic 1984 VW Golf C ("C" stands for Crisis, absolutely no electronics, it even had contact breakers instead of electronic ignition) was almost dead because of the self-discharge of the battery. I would recommend a trickle charger if you are leaving a car garaged for a long time.

Present cars: 1994 Volvo 480 GT 2.0i Vase Green, 2010 Volvo V70 2.0F Momentum Mystic Silver
Past: 1981 Talbot-Matra Murena 2.2 Rouge Mephisto, 1995 Volvo 480 GT 2.0i Paris Blue

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