Electrical Problem, Please Help
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
Electrical Problem, Please Help
i thought my batttery was shot so i got a new one. now that one went dead after sitting only 3 days. a mechanic told me i must have a draw somwwher and to get a 12 volt test light and check all fuses to see whats drawing power. can someone tell me how to do this? thanks, nutsy.
Cruising
Joined: Apr 2008
Posts: 11
Likes: 0
From: Houma LA
it can be tricky to find where the electrical drain is in your car. Mine is somewhere in the radio that I stupidly let best buy install. One of the higher ups in the corvette club I belong to suggested I put a battery disconnect or kill switch. I put a brand new battery (Optima I beileve -- one of the best so says the guy at autozone better be for $200) and hooked up the kill switch (about $20 for the switch and cables comes with two 'keys' for it) and haven't had a problem with my battery killing since.
try that if you're looking for a quick fix for now while you try to find out the underlying cause.
Best of luck!!
try that if you're looking for a quick fix for now while you try to find out the underlying cause.
Best of luck!!
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
ok heres what i did so far. i put the test light on diconected neg. cable and held to bat. when i got to lighter, clock fuse light went out. clock works but lighter dont. this is where problem is i think. what do i do now?
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
All that test did was tell you what has power on it. Here is what you need to do:
Disconnect the + battery cable and connect the test light between the + cable and the + post on the battery. With everything off and doors shut, the light should not be on.
If it does you have verified your drain. Now, do the easy stuff first, disconnect the alternator, see if it goes off, if it does alternator is bad.
If not, start removing fuses 1 at a time and see if the light goes out, start with the CTSY fuse. When you find the bad circuit the light will go out.
The fact that the cigar lighter does not have power indicates the connector has come off the bottom, or bubba has been in there.
Disconnect the + battery cable and connect the test light between the + cable and the + post on the battery. With everything off and doors shut, the light should not be on.
If it does you have verified your drain. Now, do the easy stuff first, disconnect the alternator, see if it goes off, if it does alternator is bad.
If not, start removing fuses 1 at a time and see if the light goes out, start with the CTSY fuse. When you find the bad circuit the light will go out.
The fact that the cigar lighter does not have power indicates the connector has come off the bottom, or bubba has been in there.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
All that test did was tell you what has power on it. Here is what you need to do:
Disconnect the + battery cable and connect the test light between the + cable and the + post on the battery. With everything off and doors shut, the light should not be on.
If it does you have verified your drain. Now, do the easy stuff first, disconnect the alternator, see if it goes off, if it does alternator is bad.
If not, start removing fuses 1 at a time and see if the light goes out, start with the CTSY fuse. When you find the bad circuit the light will go out.
The fact that the cigar lighter does not have power indicates the connector has come off the bottom, or bubba has been in there.
Disconnect the + battery cable and connect the test light between the + cable and the + post on the battery. With everything off and doors shut, the light should not be on.
If it does you have verified your drain. Now, do the easy stuff first, disconnect the alternator, see if it goes off, if it does alternator is bad.
If not, start removing fuses 1 at a time and see if the light goes out, start with the CTSY fuse. When you find the bad circuit the light will go out.
The fact that the cigar lighter does not have power indicates the connector has come off the bottom, or bubba has been in there.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Lets be clear. So what you're saying, is that with the doors shut, everything off, and a test light between the POS cable and the POS post, the light is out?
That means either the battery is currently dead, you don't have a draw, or you have already eliminated the draw.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
Lets be clear. So what you're saying, is that with the doors shut, everything off, and a test light between the POS cable and the POS post, the light is out?
That means either the battery is currently dead, you don't have a draw, or you have already eliminated the draw.
That means either the battery is currently dead, you don't have a draw, or you have already eliminated the draw.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Yes. One by one, open the car door, get on the floor, and install a single fuse. Get up, close the door, and see if the test light is back on.
As you install fuses one by one, if the light does not light then you have not found the circuit with the battery drain.
It's important that you close the door and make sure everything is turned off while doing this. Even the door being open will cause the test light to light up.
Just install the fuses one by one until the light lights up. The last fuse to go in is the circuit with the drain.
You can make sure the test light is connected properly by turning something on and making sure the light comes on.
As you install fuses one by one, if the light does not light then you have not found the circuit with the battery drain.
It's important that you close the door and make sure everything is turned off while doing this. Even the door being open will cause the test light to light up.
Just install the fuses one by one until the light lights up. The last fuse to go in is the circuit with the drain.
You can make sure the test light is connected properly by turning something on and making sure the light comes on.
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Sounds like you already located the troublesom circuit, CTSY.
There is an interior light timer that dies, its an orange box behind the pass side dash pad or glovebox.
Here is the schematic for my 81, yours will be close.
There is an interior light timer that dies, its an orange box behind the pass side dash pad or glovebox.
Here is the schematic for my 81, yours will be close.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
im not sure. wouldnt the clock and lighter have power going to it all the time and would it make the light go out ?
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
the light went out because you took out the CTSY fuse, that broke the ground path that was keeping the light on. Put the fuse back in and the light will come back on. Somewhere in that circuit is a ground that should not be there. If the light comes back on with the ctsy fuse in place you need to further break the circuit down: Disconnect the light timer, remove each interior light and examine the sockets, etc...
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
the light went out because you took out the CTSY fuse, that broke the ground path that was keeping the light on. Put the fuse back in and the light will come back on. Somewhere in that circuit is a ground that should not be there. If the light comes back on with the ctsy fuse in place you need to further break the circuit down: Disconnect the light timer, remove each interior light and examine the sockets, etc...
Last edited by nutsy; Apr 10, 2008 at 08:17 PM.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Dude, you don't sound stupid, but your kind of all over the place on this thing.
OK, lets step thru it a bit, you can have multiple problems.
All fuses in, everything connected normal except for the + cable, everything off, doors closed.
Connect the light between the + cable and + post, is the light on?
Remove the ctsy fuse, light still on?
OK, lets step thru it a bit, you can have multiple problems.
All fuses in, everything connected normal except for the + cable, everything off, doors closed.
Connect the light between the + cable and + post, is the light on?
Remove the ctsy fuse, light still on?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
Having a 12v source feeding to an accessory and having that accessory actually draw current from it are two different things. When an accessory is turned OFF, it should not draw any current...even though there is voltage present in the line going to it. Your problem is that something is actually drawing current when all systems should be OFF. There is a defective component or a shorted wire somewhere in the system. You use the test light to see if current is actually being drawn when all systems are OFF. The light should not come on. If it does, pull one fuse at a time, then check the test light again. When the test light does NOT come on, the fuse you just removed is hooked to the system which has the problem. Then you need to fine-tune your search to locate the area in that line where the failure is occurring.
