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

Reply to
DruG
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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.

Reply to
Tom's VR6

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.

Reply to
Papa

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.

Reply to
tonyw

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

Reply to
DruG

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.

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.
Reply to
Tom's VR6

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