12 volt short

I am experiencing a 12 volt short in my 87 Honda Accord. How would one test and trace this problem.
drumhead

If you were more specific as in what is shorting out and not working. Lights, radio, fuel pump, windshield wiper, trunk light, distributor coil...

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Karl

Pacific Accessory Corporation
Mobile Audio Interfacing Equipment
Connecting You to Your Music Since 1976

Let me better clarify this. When I leave my car unattended for more then 24 hours the battery goes dead. I believe this is due to some kind of short however I am not sure of how to find.

Thanks
drumhead

Get a multimeter and set it to measure amps. Pull the positive battery cable and place the meter inline (between the battery and cable). Next pull and replace fuses one at a time untill your amp draw goes away, BINGO. Next trace out what is in that circuit and remove each accessory one at a time untill the amp draw again goes away this will be your culprit. My bet would be on a power antenna problem or maybe a faulty ign. relay. Hope this helps. Good luck!

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R Jackson
Owner/Installer
TRM Emergency Vehicles
Information is advice only and should be confirmed with OEM or quality test equipment.
Boyertown, Pennsylvania

You need to use a DMM to measure current draw so you can determine if there is still on or in some rare cases, shorted wires. First you have to be sure that all doors are closed and nothing is on (Some vehicles may have circuits that stay on for sometime and others that turn on every hour or so to do some diagnostics then turn off, so keep that in mind). If you have a GM vehicle with RAP make sure it turns off. You will have to remove the positive battery cable and connect the black test lead of the meter to the battery cable and the red test lead to the positive battery post. You should measure some where between 5ma to 10ma. If you have an aftermarket alarm, full blown with all accessories, then you might measure up to 60ma. If you measure less than 60ma, then your battery needs to be replaced. If you are measuring more then as copcarguy said, remove and replace one fuse at a time until you find the one fuse that is the suspected circuit. From there you should be able to determine what is being powered from that fuse and is causing the current draw.

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Karl

Pacific Accessory Corporation
Mobile Audio Interfacing Equipment
Connecting You to Your Music Since 1976

Thanks to all for your help.
drumskin

I use a 12 volt test light instead of a DMM. I unplug fuses and wiggle wires while watching the light. A change in brightness will tell me where the short is.

Found the circuit going to the clock being the culprit.
Thanks to all
drumskin