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NO SOUP 4 U
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Discussion Starter #1 (Edited)
I know many of you have com across this several times. We all dread it. Ive got a short in my car. Maybe, my battery is getting drained. Or my battery is dead.
Alot of people just hate when they have electrical problems. Just the thought of all those wires. Im gonna give you guys some help. Make locating the problem a little easier.

Lets start off with what you are gonna need.
Go to any parts place and get a test light probe. One with a alligator clip on it.
I have a couple different ones.
Lets start off by removing the negative terminal off of the battery.
Ill test to see how much voltage ive got flowing first. Connect one end to the terminal touch the other to the battery's negative post. Make a note of the voltage.
In most cases a draw of 30-40 mA is ok. That draw is for such things as you ECU's memory, or your radios memory and or clock.
Take the meter and set it aside.
Now lets connect the test light up. Clip the alligator clip to the negative terminal. The probe end I have my cut off so its one about and inch long Ill take a worm gear clamp and secure the probe end to my negative post of the battery.
One a side note... I also have a 1156 bulb with a socket I will use. You could connect this the same way as the probe. The bulb is much easier to see than the probes light.

So now you have it connected.
If the light is off.... probably dont have a short. or a draw on the system. Open a door, make the dome light come on. Does the light come on? Well you know your tester works.
Look at the light... is it really bright or is it just on a little? The more of a draw there is on the battery the brighter the light will be.
Ok..... Lets find the draw. Open the fuse/relay panel up.

I have a piece of 1" or 2" foam to stick my fuses and or relays in. Just keep track of what fuse you are pulling out of where. Lets start with one fuse. is the light still on? Keep pulling fuses and relays till you locate the one that turns the light off. Make a note of any fuse or relay that you pull out that makes the light go dim or off. The ones that cause the light to go dim or off are the circuits that are causing you battery drain. Its common sense now that you know how to look for it.

I think one important area to look is see if that light in the rear of the hatch got bumped and is on. Ive had it happen a couple of times. One area that is a cause of battery drain is believe it or not, the cigarette lighter. All of our little gadgets that we carry with us that need to be recharged. Ive seen so many cigarette lighters dead in cars just because of all the crap people plug in to them. We didnt have such a demand on this area of the car back in the MKIII era. Now we do.
One other area can be under the fuse box under the hood.
If the light stays on no matter what you have removed then its more than likely going to be a short in a harness.
Just keep pulling fuses relays till its off. Once you start plugging items back in.... as soon as the light comes on Theres your problem. Just leave Alarm and radio fuses out. :)
Ok good luck. I hope you guys can find any shorts and battery drain now.
 

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Banned
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Ground out each one of the fuses in the box to find where the drain is coming from, then you can either yank that fuse to stop it draining, or use that knowledge to find it.

Say the circuit that's draining it is the radio fuse. Then you know roughly where the problem is.
 

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Oldest "trick" in the book....but for those who didn't know its well needed knowledge! Thank you for taking the time to type this up IamWedge
 

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Frozen Lake Driver
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1,292 Posts
I still love to learn all these golden tricks for finding PITA problems.
Awesome write up, thanks for sharing your methods!!!
 

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Poopra owner
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565 Posts
you can also use a voltage test meter and do this without pulling the fuses. there's two little spots on the back of each fuse where the metal is exposed so you can probe them with a test meter. you can see where the draw is by going thru your fuse boxes probing each fuse.. im not knocking the test light method, it works very well, im just giving people another option in case they have a voltage meter instead of a test light.
 

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Ive checked everything in my fuse box and havent found anything yet. I have a horrible draw on my battery (fully charged it will be dead in a day and a half) and I think its causing other problems for my car. I havent checked the lighter yet. but if i do have a short in my harness which has been extended how do I find it?
 

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NO SOUP 4 U
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1,683 Posts
Discussion Starter #7
Like i stated above just start pulling relays and fuses. Once thedraw has been located you will then be able to localize it a little easier.

Id Start with the Radio and Alarm then go from there.
 
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