finding a short

Hi there, I'm just fishing for somewhere to start. You see I have an 86
golf and its got an issue with draining it's battery. Does anybody have any
clues on how to start looking for a short?
I tried checking the voltage on a my new battery before I put it in the car
(12.73) and after it was installed with the car still completely off (12.61)
However I have no idea what this means.

Thanks for any help
-Andrew

In rec.autos.makers.vw.watercooled, DruG wrote:

>Hi there, I'm just fishing for somewhere to start. You see I have an 86
>golf and its got an issue with draining it's battery. Does anybody have any
>clues on how to start looking for a short?
>I tried checking the voltage on a my new battery before I put it in the car
>(12.73) and after it was installed with the car still completely off (12.61)
>However I have no idea what this means.

Monitor the current drain from the battery with an ammeter or a
light bulb. Pull fuses until the draw drops. Figure out what that
fuse controls.

As I am sure you know, a short can be anywhere, and can be at some very
difficult to get to locations (under the dash, on the firewall hidden by
engine components, under the floor, etc.).

Unless you have the experience, your best bet is to take your car to a good
mechanic. Often there are good ones at small "Mom and Pop" garages that
specialize in small cars, and they are a lot less expensive than the VW
dealerships because their overhead is much lower.

If you are determined to do it yourself, at least get yourself a Bentley
service manual.

Hi,
The suggestion to pull individual fuses while watching the amp meter
or test light is a good one. Note, some items normally draw current,
such as the clock, but not enough to drain the battery in normal use.

How long does it take for the battery to drain? Overnight or days?

For some obvious places to check:
- If draining overnight, check that the dome light, glove box light,
and trunk light are turning off when the door or hatch are closed. It
may sound obvious, but it's happened. In our '85 Golf a youngster
turned on the dome light to "all ways on" thinking it was the "door
actuated" setting. The battery was dead by morning. More chronically,
on our glove box, the door is warping from constant pressure on the
light switch. I'm expecting the door to warp enough for the light to
stay on.

- A long shot, did you replace the radio? Some new radios go into
standby which draws current instead of turning completely off.

- If draining rather slowly, check the alternator, it may not be
charging. Again consult Bentley for diagnostic steps.

Good luck.

Thanks all of you. I do have a bentley and the radio was done recently.
I'll try the fuse thing. One last question. Does the voltage drop indicate
current draw or is it just all those extra wires the voltage now sits in?
Does that make sense?
I have a pretty nice digital multimeter but itonly goes reads up to 500
milliamps and I'm sorry to say I don't really know how to use the thing.

Cheers,
-Andrew

"tonyw" > wrote in message
ups.com...
> Hi,
> The suggestion to pull individual fuses while watching the amp meter
> or test light is a good one. Note, some items normally draw current,
> such as the clock, but not enough to drain the battery in normal use.
>
> How long does it take for the battery to drain? Overnight or days?
>
> For some obvious places to check:
> - If draining overnight, check that the dome light, glove box light,
> and trunk light are turning off when the door or hatch are closed. It
> may sound obvious, but it's happened. In our '85 Golf a youngster
> turned on the dome light to "all ways on" thinking it was the "door
> actuated" setting. The battery was dead by morning. More chronically,
> on our glove box, the door is warping from constant pressure on the
> light switch. I'm expecting the door to warp enough for the light to
> stay on.
>
> - A long shot, did you replace the radio? Some new radios go into
> standby which draws current instead of turning completely off.
>
> - If draining rather slowly, check the alternator, it may not be
> charging. Again consult Bentley for diagnostic steps.
>
> Good luck.
>

In rec.autos.makers.vw.watercooled, DruG wrote:

>Thanks all of you. I do have a bentley and the radio was done recently.
>I'll try the fuse thing. One last question. Does the voltage drop indicate
>current draw or is it just all those extra wires the voltage now sits in?
>Does that make sense?

Voltage drop.... What makes you say you have voltage drop? Voltage
drop to me would mean that the voltage across the battery was higher
than at some other place where you would expect to show battery
voltage.

If you are simply referring to the battery being (12.73) and after
it was installed with the car still completely off (12.61), that
does indicate some current draw, but perhaps not an abnormal amount.
Having the voltage drop to 11.5 after a day or two would be
significant.




>I have a pretty nice digital multimeter but itonly goes reads up to 500
>milliamps and I'm sorry to say I don't really know how to use the thing.

500 milliamps may not be enough. If your battery is not going down
over night, then it may well be. But you may not have a short at
all.