Topic: alternator question

[motoracer]

Hey guys got my dual battery setup in and got a 130 amp alt . I was doing some testing today ,and it puts out 14.7 volts at the batteries  . I turned my 6 lights and eletric fan + my stock lights on high beam ,and it was 12.3 volts at the batteries at idle(about 900rpm.) but at the back of the alt it showed 13.4 volts with everything on.  It has a 8 gauge wire going from alt to battery .So heres my question  should i run a 4 gauge from my alt to battery?  I have a winch but didnt try it out while testing to see what my voltage was.

[junya92toy]

Its working just fine.

[jimbo74]

you could upgrade, but it isn't going to make a huge difference.... hopefully that winch isnt running 8 gauge though.....

14.6 is the ideal voltage of the alternator running, but you have to then figure in how much stuff you were purposely using to try and drain it.....

as long as you aren't using all that stuff with the engine off, you are fine...

[myyota]

Hey guys got my dual battery setup in and got a 130 amp alt . I was doing some testing today ,and it puts out 14.7 volts at the batteries  . I turned my 6 lights and eletric fan + my stock lights on high beam ,and it was 12.3 volts at the batteries at idle(about 900rpm.) but at the back of the alt it showed 13.4 volts with everything on.  It has a 8 gauge wire going from alt to battery .So heres my question  should i run a 4 gauge from my alt to battery?  I have a winch but didnt try it out while testing to see what my voltage was.

Yes, definatly upgrade the wire to the alternator to 4 gauge, if you don`t that wire will get hot under a load and melt and short out. I just got a 160 amp alternator for my 86 4Runner and im upgrading the power wires to 4 gauge so i won`t have any problems with the extra power.

[emsvitil]

6 lights at 55 watts (min) and 12.3 volts is 6 * (55/12.3) = 27 amps

15 amps for fan, 20 amps every thing else,    = 62 amps.....

62 amps at idle speed sounds about right............


With 4 gauge, you'll  won't lose 1.1 volts, probably about .4 volts

[motoracer [OP]]

ok thanks but does it matter that my  alt wire is going into my fuse box then to my battery?  all my wires for my winch and both batteies are 4 gauge, and so is my ground wires are 4 gauge.

[motoracer [OP]]

       I was looking at my wiring today and the wires coming out of the alt is a 8 gauge but after it goes into the fusebox it comes out it looks alot smaller . how would i go about wiring it. ive rewired a alt before in a old dumptruck and run 1 wire from alt right to battery. the fuse box it got me a little stumped.

[emsvitil]

When you're running, the load is being distributed by the fusebox, and the wire from the alternator to the fusebox is more important than the wire from the fusebox to the battery........

Just upsize the wires as best you can.     4 Gauge may not fit, so may 6..........

Or double up the wires.   

Adding a 10 to an 8 would be the equivalent to about a 6. 

Two 8s are a 5 gauge.

[motoracer [OP]]

thanks guys  i ran a 4 gauge it my fusebox then put all the wires that was hooked up on the other side of the fuse . ( i could run my stock 8 gauge alt wire and that new 4 gauge wire to the fuse box  but ididnt)  and ran a 4 gauge from the fusebox  to the battery. and you hit it right in the head emsvitil it went to .4 volt and even put more volts to my dual battery solenoid.

[myyota]

       I was looking at my wiring today and the wires coming out of the alt is a 8 gauge but after it goes into the fusebox it comes out it looks alot smaller . how would i go about wiring it. ive rewired a alt before in a old dumptruck and run 1 wire from alt right to battery. the fuse box it got me a little stumped.
[/quote]

That little wire comming out of the fuse box to the battery is whats charging the battery, in my opinion its to small to carry much of a load, i would upgrade it to at least an 8 gauge wire, or you could run the wire from the alternator right to the battery and run a wire from the battery back to the fuse box. That way your battery will recieve direct power from the alternator.