Currant Draw Test
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Joined: Oct 2005
Posts: 75
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From: Flagstaff Arizona
Currant Draw Test
Ok so I searched for this and could not find what I was loking for. I seem to be killing my yellow top awfully fast (2 weeks of not driving and I can't start the car). I wondering if there is a short in the system somewhere. I've done a lot of work on cars over the years but I'm a real noobie when it comes to electrical stuff. How do I hook up the multi meter to find this? I'm assuming at the battery ground. Do I just use some aligater type clips? What gauge wire? Will the multi support the draw? Obvioulsy I don't plan on starting the car or anything I just want to check for draw while the car is in "rest" mode.
Thanks in avance.
MIKE
Thanks in avance.
MIKE
Drifting
Joined: Jan 2005
Posts: 1,650
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From: Bakersfield Ca
Set your meter to read the highest level amps that it can read. You will get current draw from your hood light so disconnect that first. Also, wait for the dome lights to go out as well. Disconnect one battery cable (doesn't matter which one) and connect your meter between the battery cable and the battery. If you read a negative number, then swap the meter leads around. Once you have it all connected, then start stepping the amp range down until you get a reading. If you have a clamp on amp meter, just clamp it to the positive lead and set it to read amps. Your battery should last longer than 2 weeks. 
I used to live in Flagstaff, loved it!
I used to live in Flagstaff, loved it!
Pro
Joined: Jun 2007
Posts: 631
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From: Joppa AL
Some good pics here:
Pro
Joined: Sep 2007
Posts: 735
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From: Bucks County Pa
Need Maintainer for Extended Non Use
Hi, For a new battery 2 weeks of non use will just discharge it a bit. But if that is your pattern of use then you should be using a maintainer,(and you need a proper one that is capable of maintaining a yellow top, not all are). A battery will start to sulphate if it is not kept at least at 90% charge state. The more times this happens the battery slowly loses its ability to hold a full charge, so over time, even a relatively short time the battery lasts less and less when not being kept charged, hence being discharged below the voltage necessary to start the car, even in a 2 week inactivity period. The common wisdom is that c5 owners need to use a proper maintainer when not using the car for more than a few days, especially if this is their pattern. Red and Yellow top Optimas are even more susceptible to this type of situation, and need higher amp rated maintainers to keep them charged,(at least 1.25 amp float chargers).
So if you find that you do not have excessive draw on your system, get a good de sulphating maintainer and you may save the battery for a while.
Good Luck
So if you find that you do not have excessive draw on your system, get a good de sulphating maintainer and you may save the battery for a while.
Good Luck
Thread Starter
Advanced
Joined: Oct 2005
Posts: 75
Likes: 0
From: Flagstaff Arizona
Hey all, thanks for all the pics and info. I'm going to check the draw tomorrow. The yellow top is only 5 months old so I was a bit shocked when I did not have enough to get the car started after a 2 week sitting time. I thought it might be the stereo (I have a fairly big setup) so I DC'd the main breaker and still the battery seemed to lose charge. So now I'm guessing that is something in the factory wiring. Thanks for the Pics that helped out alot. This time of year it is hard to drive regularly (it snowed again today) so 2 weeks is fairly norm until the weather becomes more stable.
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Joined: Dec 2003
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From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
It's electrical current!
