Need help with Fuse Box
Thread Starter
Pro
Joined: May 2002
Posts: 689
Likes: 0
From: MI
Need help with Fuse Box
I finally borrowed a voltmeter from school, and checked for the reason my battery keeps dying while car is off.
The fuse box ports marked 'Ign' and 'Alt Ign' are drawing 12+ volts while car is off, and keys aren't in. These are the only two that don't read zero volts. How can I correct this.
Thanks for the help.
The fuse box ports marked 'Ign' and 'Alt Ign' are drawing 12+ volts while car is off, and keys aren't in. These are the only two that don't read zero volts. How can I correct this.
Thanks for the help.
Melting Slicks
Joined: Mar 1999
Posts: 2,845
Likes: 2
From: Apex NC
Re: Need help with Fuse Box (Double_0_7)
It ain't volts you're lookin' fer, it AMPS. You need to disconnect anything that's drawing current when the key is off. As you mentioned, those two ports are the ones that have power regardless of the key position. Are these fused connections or just straight ports? If fused, take out the fuse, if direct port just unplug the lead on the lug. Put the volt meter in "amp" mode. Then place one lead on each side of the fuse holder (or between the lug on the fuse box and the wire to the circuit) and see what amount of current is flowing through each circuit.
The the fun begins. You've got to isolate the component in the circuit that's drawing the excess current. Start yankin' bulbs and disconncting wires until you've got it fully isolated. A thorough wiring diagram is a requirement for this.
Good luck. Electrical problems Suck.
Shannon
The the fun begins. You've got to isolate the component in the circuit that's drawing the excess current. Start yankin' bulbs and disconncting wires until you've got it fully isolated. A thorough wiring diagram is a requirement for this.
Good luck. Electrical problems Suck.
Shannon
Le Mans Master
Joined: Jan 2001
Posts: 9,244
Likes: 221
From: Dryden MI
Re: Need help with Fuse Box (Double_0_7)
There will be voltage on some fuses in the fuse box while the ignition is off. Door lights,cigarette lighter, brake lights etc. will work with ign off A few suggestions before you start disconnectiing things. Check or have your alternator checked first. Your alternator will drain a battery while the car is off. Check your glove box light and cigarette lighter, make sure that they are off. Good Luck Roger L. Gibbons
Thread Starter
Pro
Joined: May 2002
Posts: 689
Likes: 0
From: MI
Re: Need help with Fuse Box (Roger L. Gibbons)
It's a new alternator, so it shouldn't be a problem I would guess, but where do I check it just in case? And is anything that is drawing current while the car is off the culprit?
Burning Brakes
Joined: Jun 2002
Posts: 792
Likes: 2
From: Norcross GA
Re: Need help with Fuse Box (Double_0_7)
The draw adds up. For example, the clock and the stereo draw a certain amount of power while the car is off but don't really hurt anything. The trick is to find the circuits that shouldn't be drawing current and are. Each additional circuit will draw more power eventually killing the battery. This is the process of unplugging circuits that shouldn't be drawing power and finding that your draw on the amp meter reduces indicating that they are.
For example, if the interior lights were all remaining on when they shouldn't be (ever leave the door open and kill the battery), they would drain the battery in a short time.
Bob
[Modified by Bobchad, 4:09 PM 9/4/2002]
For example, if the interior lights were all remaining on when they shouldn't be (ever leave the door open and kill the battery), they would drain the battery in a short time.
Bob
[Modified by Bobchad, 4:09 PM 9/4/2002]
Le Mans Master
Joined: Jan 2001
Posts: 9,244
Likes: 221
From: Dryden MI
Re: Need help with Fuse Box (Double_0_7)
I am not sure, but I might be able to help. The red lead that connects to the alternator has 12 volts to it at all times. It comes from the starter lug. Disconnect the battrery first, put the meter in series with the battery + terminal and the battery cable. Make sure that the meter is set to amps and not milli amps before you connect it to the batttery. Look at your amp draw and make a mental note of the reading. Disconnect your leads then disconnect the red wire to your alternator, remember that wire has 12 volts to it so don't let it ground out, and reconnect your meter. Compare the values. If the current draw has decreased, I would suspect the alternator. If not then start pulling fuses until you notice a large current drop. Roger L. Gibbons
Instructor
Joined: Jun 2001
Posts: 231
Likes: 0
From: Cedar City UT
Re: Need help with Fuse Box (Roger L. Gibbons)
Most volt meters only read milliamps. If thats the case with your meter you can use a simple test lite made of a 12v lite bulb and 2 pieces of wire 1 soldered to the case and 1 to the tip or go to Pep Boys/Autozone and get a cheapy test lite from them. Then follows Rogers advice and you should be on your way to finding your drain. LOL
Bob
Bob
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Cruising
Joined: Sep 2002
Posts: 13
Likes: 0
From: Columbia MD
Re: Need help with Fuse Box (Double_0_7)
9 times out of ten the only problem is a bad battery. Really, have the battery place check it for you. They will do it for free. It will save you hours of wasted time. ask me how I know.
