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what is on circuit BTN

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Old 03-25-07, 07:54 PM
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what is on circuit BTN

so my battery has been getting drained so I figured out (with the help of this site) that it is circuit BTN. but what I need to know is what is on that circuit like is the raido or the clock on there. it is the 60 amp fuse in the engine bay.
Old 03-25-07, 08:02 PM
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its under the dash. its like a 20amp or 15amp.. its nothing huge like a 60. the 60amp is like the battery and that will shut everything down. just look up on how to test for drains. an easy way that will prolly work on our cars cuz they are older.. just disconnect the negative and get a test light and connct it in series. and it should be lit up. make sure all the doors are closed too. and if its lit up.. start pulling fusses under the dash till it goes out. that usually works
Old 03-25-07, 08:07 PM
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I did the test with a volt meter and I found it was THAT circuit that is draining my battery. but I want to know what is in that circuit.
Old 03-25-07, 08:26 PM
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just to let evary one know it is an 88 5-speed n/a
Old 03-25-07, 08:33 PM
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Im having the same problem right now with my room circit. and specifically my cd player. with ign power lead connected ( and ign off ) in getting 1amp draw!, if i disconected it ( leaving the constant 12v memory feed connected ) i drop down to .69amps

is the room circit supposed to have .69amp draw on it?

PS sorry for thread jacking
Old 03-25-07, 09:59 PM
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To do a PROPER test for an Amp draw, you must disconnect the NEGATIVE terminal. set the multimeter to amps. Connect negative to batt and pos to the negative terminal. See what you amp draw is. If it is higher then 0.500 amps, you have something drawing down your battery. (most clock/ECU's do not draw more then that down with ignition off in most cars)

Once you have established what your drawdown is, start pulling fuses until you get below the 0.500 amps. THAT will lead you to where your draw is.

If you need diagrams, your gonna need either a haynes manual or the FSM.
Old 03-25-07, 10:06 PM
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Connect negative to batt and pos to the negative terminal.
To clarify, you connect the negative car terminal to the battery negative post. Then touch the positive car terminal to the NEGATIVE battery post. DO NOT reverse the battery terminals on the battery... NOTHING touches the positive battery post!

That was easy enough to mis-read, just clearing that up.
Old 03-25-07, 10:19 PM
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what does that do tho? then where do you put the multi meter? i just removed the negitive terminal form the batt and put the multimeter between the teminal and the and earth battery lead
Old 03-25-07, 10:28 PM
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OK. Take the NEGATIVE of the Multi meter and put it on the NEGATIVE battery post. Take the POSITIVE of the multimeter and put it on the NEGATIVE BATTERY CABLE. Your putting the MM in series with the battery and cable. The AMPS that are being drawn while the car is off and doors closed will pass through the MM and you will then be able to pull the fuses and find your draw.


Sorry for the confusing post lol. What this does is let you see how many AMPS are being drawn down while the car is off and nothing on at all (door light, radio ect ect, no key even in ignition)

If it is above 0.500 amps you have something drawing too much amps. Start pulling fuses for different things and once the amps draw down, yo uhave found where the draw is. Once you do that, you have to find the EXACT issue at hand in that circuit.
Old 03-25-07, 10:33 PM
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To clarify even more.

1. disconnect battery negative cable.
2. set multimeter to AMPS.
3. place multimeter negative lead on the battery negative.
4. place multimeter positive on the negative cable you disconnected from battery.
5. see what your AMP draw is. If ABOVE 0.500 amps proceed to step 6.
6. Start pulling fused to find the circuit that is drawing down your battery. This happens when the AMP draw goes below 0.500 AMPS.

If the AMP reading is already BELOW 0.500 AMPS, you could have an issue with either the BATTERY or charging.
Old 03-25-07, 11:24 PM
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thanks for the help. if any one else has any other other ideas that whould be great.
Old 03-26-07, 12:34 AM
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The BTN fuse feeds the following fuses (and systems) in the interior fuse box:

ABS: ABS system
ANTENNA: Antenna, power lock
HAZARD: Hazard lights
ILLUM: interior lights, taillights, HVAC system
ROOM: Interior lights, alarm, clock, EGI system
STOP: Brake lights, horn

Repeat the test procedure above with these fuses, and once you know what fuse the probelm is on, start unplugging components until the current draw goes away.
Old 03-26-07, 07:22 AM
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All this can be found in the FSM wiring diagram. It would be a good idea how to learn to use it if you don't. I've found it very useful after learning.

Originally Posted by 1SxyRXy
its under the dash. its like a 20amp or 15amp.. its nothing huge like a 60. the 60amp is like the battery and that will shut everything down. just look up on how to test for drains. an easy way that will prolly work on our cars cuz they are older.. just disconnect the negative and get a test light and connct it in series. and it should be lit up. make sure all the doors are closed too. and if its lit up.. start pulling fusses under the dash till it goes out. that usually works
You really should know what you're talking about before you do so.

Old 03-26-07, 04:59 PM
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Originally Posted by turboefini88
OK. Take the NEGATIVE of the Multi meter and put it on the NEGATIVE battery post. Take the POSITIVE of the multimeter and put it on the NEGATIVE BATTERY CABLE. Your putting the MM in series with the battery and cable. The AMPS that are being drawn while the car is off and doors closed will pass through the MM and you will then be able to pull the fuses and find your draw.


Sorry for the confusing post lol. What this does is let you see how many AMPS are being drawn down while the car is off and nothing on at all (door light, radio ect ect, no key even in ignition)

If it is above 0.500 amps you have something drawing too much amps. Start pulling fuses for different things and once the amps draw down, yo uhave found where the draw is. Once you do that, you have to find the EXACT issue at hand in that circuit.
I understood it.. I just had precognitions of "I checked my amp draw and smoke came out of my ECU" threads. So I just figured I'd clarify.
Old 03-26-07, 10:09 PM
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ok I found my short today. and pulling the fuses did nothing for me. while I was waiting for the voltage to drop I heard a burrrrr noise comeing from the throlty body area. so I put my ear next to the throlty body and heard the noise. so I walked over to the drivers side and put my ear next to the throlty body and I chould hear it better so I started looking around there better and I looked at the bac. so I pulled of the connecter and the noise stoped. and then I looked at the voltmeter and it was going back up. so just to make sure I out the connecter back on and then the noise came back. so this means that the bac is the short so now I have to buy a new bac. I dont know if this helps you out micaheil but this is my short.
Old 03-27-07, 03:14 AM
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Originally Posted by black_88
so this means that the bac is the short so now I have to buy a new bac.
Don't just to (bad) conclusions so quickly.

Firstly, a short is a direct path from the battery's positive terminal to ground, and results in either a blown fuse or a lot of sparks and stuff melting. A current drain like you have is not a short.

Secondly, the BAC valve is supposed to buzz, but only when the ECU is driving it. The ECU only works when the ignition is on. Obviously the ignition has to be switched off when you do this testing. So was the ignition on or off?
Old 03-27-07, 07:20 AM
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it was off. and there was no blown fuses.
Old 03-28-07, 01:50 AM
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The BAC valve gets power from the main relay, which is turned on by the ignition. So there should be no power at the BAC valve to cause a buzzing when the ignition's off. If there is, there may be a problem with the main relay not turning off, which would probably cause the battery to be drained. However neither the BAC valve or main relay get power from the BTN fuse. Do you still have a current draw on that circuit? 40-50mA is normal.
Old 03-28-07, 08:20 AM
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ok so I went and unpluged the BAC and I hooked up a volt meter to the battery and the voltage was not droping. I sat there for a half hour with the volt meter connected and the volts never droped. so the next morning I went and tried to start the car and the battery was dead. so dose any one have any idea where the short chould be.
Old 03-28-07, 10:55 AM
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[QUOTE=NZ_87_TURBO]what does that do tho? then where do you put the multi meter? i just removed the negitive terminal form the batt and put the multimeter between the teminal and the and earth battery lead[/QUOTE......
Attached Thumbnails what is on circuit BTN-amps.jpg   what is on circuit BTN-amps2.jpg  
Old 03-29-07, 03:29 AM
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Originally Posted by black_88
ok so I went and unpluged the BAC and I hooked up a volt meter to the battery and the voltage was not droping. I sat there for a half hour with the volt meter connected and the volts never droped. so the next morning I went and tried to start the car and the battery was dead. so dose any one have any idea where the short chould be.
Are you not reading anything being posted? You don't have a short, and you need to be measuring current (not voltage) to find what circuit is draining the battery as per the instructions posted several times.
Old 03-29-07, 08:48 AM
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So, if the meter can't measure amps, then disconnect the LARGE wire on the alternator and then try starting the next morning. If the batt is still up, then the alternator is involved.

Or, disconnect the wire that feeds the ignition switch. It's a pure black wire with a single spade connector just below the engine fuse box. That black wire also splices to the large wire on the alternator. The alternator output wire.
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