Current limiting fuse from alternator

If the alternator is wired from the battery, through the factory fuse box, then would the main fuse need to be upgraded to a higher amperage? How does the current draw by the amp system have an effect on the max current that the alternator can provide to the battery? I feel that it would be limited by that fuse. For example: I have an absolute maximum of 110 A being drawn by the stereo. This is delivered via a 2 gauge from the battery. However, the alternator runs through the fuse box with an 80 A fuse protecting it. If the amps are running at max, the alternator would not be able to keep up because it's limited by that 80 A fuse.

Am I thinking correctly?

-------------
WTB: Black Leather Acura GSR seats

Yeah, and why haven't you upgraded your alternator yet? JK, but really, when you do, you need to wire the output of the alternator right to the positive battery post, with an appropriate wire size... do not try to run a HO alternator's output through your stock wire.

Actually, I just re-read your post, and it sounds like you are asking "Is my 80A fuse preventing me from getting all the current I paid for in this HO alternator?" And the answer to that is also a RESOUNDING yes. IF you have an HO alternator, you SHOULD wire it directly to your battery. If you do not, if you prefer it running where it is, you need to upgrade your stock alternator cable to the fuseblock, AND upgrade the fuse in the fuseblock to a correct fuse size.

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

One question. When he does this, does he just add a wire and run it straight to the battery from the alternator and keep the wiring that is on the car now as it is? Or does he need to replace the wires he has now with the upgraded wire? (I guess that's 2 questions) 

-------------
'85 Toy

LOL, I havent upgraded my alternator yet because I just finished laying sound deadening material. I will be ordering my HO alt from Dom pretty soon.

Okay this makes sense to me now. I will remove the lead that runs from the alt to the fuse box since it will no longer be necessary. Then I will upgrade the cable to the alt, fuse it appropriately, and hook it to the battery. This will allow the electrical system to use as much current as it needs from the alternator.

Actually it may be cheaper to just upgrade the wire and get a new fuse for the fuseblock....



-------------
WTB: Black Leather Acura GSR seats

I'd like to second supradude's question. Should you both add new wire and leave the stock wire, or remove the stock wire and upgrade?

-------------
Nik
Jeeputer Progress
[|||||||||||-] 90%
Check it out.

Personally, I would not run two wires... add a new one, or replace the old one, but don't use two...

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

There seems to be a little difference of opinion here. Anyone else?

-------------
'85 Toy

What happens if the fuse on the big one (the one connected to the battery) blows, and the load is more than the smaller wire can take? Now you are in a serious overcurrent condition, and things can only get worse from there...

Just something to think about...

This is why it is NEVER good to run two wires froma source to a single load through two paths...

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Good point.

-------------
Nik
Jeeputer Progress
[|||||||||||-] 90%
Check it out.

So he needs to do away with the old wire and fuse and run completely new wiring with a larger fuse to the battery?

-------------
'85 Toy

The old wire that goes to the alternator runs from the battery to the fuse box where all the accessories pick up their power. From what it looks like inside the fuse box, these connections are fused individually and by the same fuse that we have been discussing that leads to the alternator. So what has been described is to remove the wire between the fuse box and the alternator. The fuse will remain in place. A new wire with fuse will run directly from the battery to the alternator. The fuse will be choosen to allow maximum current draw from the alternator but no larger than the draw allowed by the wire.   For example, I will run a 2 gauge from the alt to the battery. 2 gauge wire can carry 225 A max. So I would choose a 225 A fuse. However, if the wire choosen is 4 gauge and the alternator is capable of delivering 200 A, the maximum current draw allowed by the wire is 150 A. The system is limited by the wire.

-------------
WTB: Black Leather Acura GSR seats

Correct you are, sir...

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."