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Still having wiring problems.


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Battery is draining completely dead about every two days. The first day after I charge it it'll run fine, the second day if I turn on the headlights, turn signals, or brake lights the car will die from voltage drop.

 

Only mods to the battery assembly is a Maxi Fuse conversion and a battery relocation to the hatch. I'm using 4g wire for the battery relocation, running from the pos on the battery to the starter, and the neg on the battery to the engine block.

 

I'm running the positive for the Maxi Fuse block from the starter straight to the fuse box. Haven't messed with the four white/red wires coming out of the fuse box.

 

The only place there could be a drain is at the fuse block. I'm not sure where, but that's really the only place it could be.

 

My other theory is that the alternator isn't charging the battery. I know the alternator is good, but I'm not sure if it's putting out to the battery. Any suggestions?

 

I'm taking tomorrow off to work on it, if it comes down to it I'll just put the battery back in the engine bay and hardwire everything in. Really don't want to do that, but if I gotta bypass everything I'll do it.

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First, remove the positive and negative cables from the batteries. Put an Ohm-meter across the positive and negative cable. If your reading is close to 0 Ohms then you have a direct short.

 

Next, do a parasitic draw test. Make sure your battery is fully charged. Check to make sure ALL loads are turned off. Unplug anything you may have plugged into the cigarette lighter. Remove your keys from the ignition. Close all doors so the dome lights are off.

 

Disconnect the thick positive (Red) cable that goes down to the starter.

 

To start make sure your meter is set to the 10 amp DC range. Some meters have a special connector for the red probe when you are reading current. You can either do this next step by just holding the meter probes to their respective contact points (you won't get a shock from 12 volts) or you can use probes with alligator clips to snap them in place so your hands are free to do something else.

 

Connect the positive probe to the battery - either battery is fine, electrically speaking, since they are connected together by the negative (Black) wires. Polarity on digital meters doesn't matter because they are autosensing.

 

Connect the negative probe to the red cable that is still connected to the vehicle. Make sure this cable and your probe do not touch ground.

If there is a severe current draw (more than 10 amps) it will either pop a fuse in your meter or destroy it outright. That's why you need to test for a short, otherwise, your meter should now be reading the current drain on your battery.

If your vehicle has an alarm system or remote locks, the current draw may be around 2-3 amps for a few minutes after you last close the door. This is normal. If you're not sure, wait at least 20 minutes after you last open or close a door before you take a reading.

If everything is normal, you will read less than 35 milliamps, or .035 amps. If the current drain is higher than that, you need to find out what is draining your batteries: You can start by pulling fuses until the load goes away. If that doesn't reduce the draw, you need to look for a wire that is corroded or frayed.

Edited by Kris.Is.Awesome
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Hm I'll try that! Thanks for the detail. A buddy of mine has a multimeter, so I'll be getting to work on that.

 

Edit: just out of curiosity, what is the .035 amp draw from? The clock should be the only thing recieving power when the car is off, correct?

Edited by ComicArtist
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My other theory is that the alternator isn't charging the battery. I know the alternator is good, but I'm not sure if it's putting out to the battery. Any suggestions?

Perform the tests clearly outlined in the FSM.

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There are other components that will cause the normal .035 draw. ECU, Stereo, clock, Alternator, aftemarket amplifier, dome light, marker lights, tail lights, brake lights, interior light and so on.

 

If you have a draw you start pulling fuses one at a time to see which circuit it is in. Then you start disconnection each component in the circuit you found the draw in, to find the draw. If the draw doesn't go away after pulling each fuse, its in a hard wired component. Relay, Alternator, Amp, Fog lights, Blower motor and so on. In the newer cars, I have found them in the vanity sunvisors a lot.

 

I have to deal with more components then mentioned, whith a draw on a newer car. I am a Nissan dealership mechanic.

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That makes sense.

 

It would make perfect sense for the alternator to not be working, but this is the second alt I've tried and they've both tested fine.

 

So if that was the case, it would have to be the circuit going from the output of the alt back to the battery, for charging.

 

If I'm correct, the wire goes out of the alt, to a fusible link, which goes to the starter, which goes back to the battery. Would I be better off just going straight from the fusible links to the battery? It's obviously losing voltage somewhere along the way.

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Running a separate wire to the battery is not necessary and is not really desirable as it will add additional voltage drop. It will also leave a bad connection somewhere in your wiring harness that cause additional problems later. Trace the wire from the alternator and look for dirty, corroded, or damaged connections, cut wires, overheated wires, etc. You will need to unwrap the wiring harness to do this thoroughly.

Edited by beermanpete
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The FSM covers all this I recall, but check the voltage regulator and that your wiring from the alternator is actually in good repair. Sounds like you have some loose contacts somewhere. Have you replaced the fusible links? Old and corroded contents on the fusible links and other areas could easily be the culprit.

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