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How to find a electrical short?

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Old 07-19-2006, 12:17 PM
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Default How to find a electrical short?

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Old 07-19-2006, 12:28 PM
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Yup that will work. A long process but it will work.

I would first start with lights. Ie interior light or even glove compartment light.

A buddy of mine had the same issue in his track rx7. Ended up being one of those fake alarm LED's lol..
Old 07-19-2006, 12:35 PM
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Originally Posted by Jasonoff,Jul 19 2006, 12:28 PM
Yup that will work. A long process but it will work.

I would first start with lights. Ie interior light or even glove compartment light.

A buddy of mine had the same issue in his track rx7. Ended up being one of those fake alarm LED's lol..
well because I didn't know if 200mA is good enough we pulled 3 fuses already. I think one is head lights, another one is for parking lights, last one is interior light. So if the van starts tommorrow morning than its got to be one of those 3 system.
Problem will be to locate the short it self. Anyway to track that down?
Beside that he can always pull the fuse at night and plug it back it back in the morning.
Old 07-19-2006, 01:53 PM
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200 ma isn't much. You might fry the meter. Head lights draw 5 amps each (65 watts = 4500-5000ma). I think your technique it good but, the most likely cause is something you've done like add an amp or aftermarket stereo/alarm. I'd disconnect them first.

You don't have a short. If you had a short, you'd blow a fuse. What you have is something drawing current when it shouldn't. Keep in mind the ECU and stereo will ALWAYS draw current to maintain their NV RAM.
Old 07-19-2006, 03:13 PM
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non-S2k related, moving to car talk
Old 07-19-2006, 04:09 PM
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do not use your meter

its not any of your lights because you dont see them on... right?
how old is the battery, disconnect the battery, re connect in the morning, still starts?
disconnect the alternator over night.
as above, look at things that have changed, trailer hitch wiring?
start pulling fuses overnight, at first try several at once
rent/buy a clamp on amp meter from an auto parts store, maybe faster?
Old 07-19-2006, 06:10 PM
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Originally Posted by jah,Jul 19 2006, 08:09 PM
do not use your meter
Why not?

It will find the problem faster than trying stuff overnight.
Old 07-19-2006, 06:36 PM
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the current section in your meter is rated at only .2amp (200ma) max
Old 07-19-2006, 06:57 PM
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Sure if it's a rinkey dink cheapo. Mine goes to 10ADC...

But good point.

However he would measuring with the car off and fueses pulled out.
Old 07-20-2006, 07:39 PM
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battery is new. and if nothing is connected to the battery it will start next morning. I am going to buy a new voltmeter that will take up to 10amp DC and than plug fuse back in one at time and see where the reading jumps. I don't think even once I find the system that is using power I will be able to trace what is causing it, thats just too many wires to trace.

The only thing I am thinking is I run the wire into the van, attach a switch than run the wire back into the fuse box. So every night he will just flip the switch instead of pulling the fuse. Or I will have to run a relay to that fuse so it is getting power only when the van is running.


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