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Charging wire (from alt.)

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On an EA82, can I run a heavy (4gauge) wire trait from the charging post on the back of the alt. to the battery? I know that this will help get more juce to the batt., but I dont know if it will cause a problem some where down the line in the harness or the computer:confused:

Unless you are planning to run a 400 amp aternator changing to #4 wire isn't going to make any noticable difference. At that short of a distance #8 wire only has about .003 ohms of resistance and #6 has less then .002.

  • Author

I know that that #4 is over kill, but I have allways used it for all my batt. and alt. cables:drunk:

It's welding cable and it works GREAT ! I just wonderd if it will hut any thing to have a wire going strate from the alt. to the batt.:cornfuzz:

I think you are bypassing a fuse link in the charging circuit by doing this. If something shorts out in the alternator you may get a nice fire going. The 4ga. wire will provide a lot of amps for some time before it melts down.

  • Author

Good point! I never thought of that. So if I do I should add a fuseable link in the line. 65amps should do it, yes, no?

Yes.

The link from the output of the alternator to the battery is simply a piece of wire with a fusible link.

 

In your case, any fuse with a rating somewhat (but not too much) higher than the rated output of the alternator will achieve the same thing.

 

I've seen fuses used in parallel. Two 35-amp fuses in parallel equals a 70-amp fuse.

Adding the fuse by the battery will give you protection but unless there is something wrong with your factory wiring you are not really gaining anything by doing this. You can prove this by checking the voltage drop between the output stud of the alternator and the positive battery post. You should have less than 0.1 volt of drop. Your wire may add an extra 0.1 volt to the 14.5 volt charge but this doesn't really help your charging system. After a battery is charged up it will draw less current and will float charge. The best thing you can do is have a good battery with tight and clean connections to it and the alternator.

  • Author

I never thought of that before, but it makes sense! That little tid bit of info will come in handy:burnout:

I will use the 2x35A fuse Idea, 70A sould be perfect! Thanks!

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