Current Leak in electrical system

  • Thread starter Thread starter Bill
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Bill

Something is draining my battery to the point where my 1987 Volvo 240
goes dead. I had the battery loaded tested and proved good. I
installed a new Bosch alternator thinking the current was leaking
through alternator but the car battery still goes dead after 3 or 4
days of sitting in the garage. If leave the battery cables
disconnected, the battery is fine. Following are testing results with
an amp meter:

1. With the positive battery cable disconnected, at first positive
contact between Positive on Battery and Cable with a Fluke Meter, we
measure 200 mA.
2. After two seconds, the amperage reading drops down and stabilizes at
80 mA. We believe 20 mA of the 80 mA is the car clock.

I suspect some type of electronic circuit board is charging up
capacitors and then drops back to 80 mA.

Does any one have any thoughts? Does anyone have a better strategy to
diagnose current leakage?

Bill - Philadelphia
 
I had a problem with my 93 850 like that. Turns out that I had put a CD
changer in the glove box, and the light switch was not turning the glove
box light off as it should. I didn't notice the light being on because
the glove box was closed. The light was powered even with the ignition off.
 
Something is draining my battery to the point where my 1987 Volvo 240
goes dead. I had the battery loaded tested and proved good. I
installed a new Bosch alternator thinking the current was leaking
through alternator but the car battery still goes dead after 3 or 4
days of sitting in the garage. If leave the battery cables
disconnected, the battery is fine. Following are testing results with
an amp meter:

1. With the positive battery cable disconnected, at first positive
contact between Positive on Battery and Cable with a Fluke Meter, we
measure 200 mA.
2. After two seconds, the amperage reading drops down and stabilizes at
80 mA. We believe 20 mA of the 80 mA is the car clock.

I suspect some type of electronic circuit board is charging up
capacitors and then drops back to 80 mA.

Does any one have any thoughts? Does anyone have a better strategy to
diagnose current leakage?
Click to expand...

200mA isn't actually that much, so look for courtesy lights and things that
are on. I'd be surprised if that was flattening your battery in a few days.
You can try, with the multimeter installed, pulling fuses one at a time to
try and narrow down which circuit the problem is in.

Don't forget that if the radio has a memory that will draw a few mA as well,
but I'd guess at no more than 10.
 
We had this same problem with our '89 240. It was a nuisance for several
years. As long as you ran the car every day, it was fine, but if you let it
sit for a couple of days, the battery went dead. I nailed it down by
clipping the ammeter in series with the positive battery terminal (drawing
about 240 mA), and pulling the fuses one at a time.

In my case, it turned out to be a faulty door switch (to turn on the dome
light). Remarkably, turning off the dome light manually did not fix the
problem. I ended up removing the door switch (it was the right rear door,
so nobody complained).

Without the extra load of the faulty switch, just the clock and whatever is
used to store radio presets, etc., the latent current draw is about 25 mA.
 
Bill said:
Something is draining my battery to the point where my 1987 Volvo 240
goes dead. I had the battery loaded tested and proved good. I
installed a new Bosch alternator thinking the current was leaking
through alternator but the car battery still goes dead after 3 or 4
days of sitting in the garage. If leave the battery cables
disconnected, the battery is fine. Following are testing results with
an amp meter:

1. With the positive battery cable disconnected, at first positive
contact between Positive on Battery and Cable with a Fluke Meter, we
measure 200 mA.
2. After two seconds, the amperage reading drops down and stabilizes at
80 mA. We believe 20 mA of the 80 mA is the car clock.

I suspect some type of electronic circuit board is charging up
capacitors and then drops back to 80 mA.

Does any one have any thoughts? Does anyone have a better strategy to
diagnose current leakage?

Bill - Philadelphia
Click to expand...

I had one where it was the clock - the clock kept time perfectly, just
took 100 mA to do it!

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
I had the same problem twice with my 240 while living in L.A.
I used to live on a steep street and when I just pulled in front of the
house instead of the driveway, the angle of the street was enough to
turn on the trunk light.
The second time that it happened, it turned out to be corrosion on the
connector that plugs into the ECM. Sprayed it with contact cleaner and
hasn't happened since. Also, check the wires that come out of the
firewall on the right side of the car. If the wires have deteriorated to
the point where the insulation is flaking off, possibly they are
touching and causing a drain.

Good Luck
 
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