Alex6969

I just instaled my FD alt, works like a charm, but i have a question. should i replace my 80 amp main fuse with 100 amp one?

thanks guys

Aaron Cake

iTrader: (1)

Not really necessary. It's very unlikely that you will be running the FD alternator at it's max output (which is actually a bit higher then 100A) for long enough to blow an 80A fuse. It would take 100A hours to blow an 80A fuse, if it blew at all.

Alex6969

ok aaron thanks

RETed

It's a very interesting and valid question, and Mr. Cake is right.
Technically, you didn't raise the current draw on the "other side of the alternator", so you don't need to upgrade the fuse to a higher rated one.
Now, if you're pumping some big *** stereo through the stock wiring, you should get a good scolding for doing that.


-Ted

NZConvertible

Ted's right, any big additional electrical loads like amp'd stereos and electric fans should be fed directly from the battery via their own fuses. That way the load on the stock electrical wiring (and the MAIN fuse) isn't increased.

Wankel7

Sweet lord...did I just see three of the FC brains agree?

Yikes!

TiGeRC|aw

holla!

Alex6969

wow and it was on my thread too! I feel very special. one last question, I'm not seeing the amount of votage as I normaly see around the forum. Granted I'm only relying on the stock voltage gauge. I do have a slightly underdriven dual alt pulley that i modified (from bonzaitoyota) so that could be the main reason, what are some of your sugestions for increasing my voltage?

Aaron Cake

iTrader: (1)

How much voltage are you seeing? And you should probably verify it with a proper voltmeter instead of relying on the stock one.

Alex6969

I'm usualy seeing right at or right below 14 w/ just the radio and car on. when everything is on I'm seeing right at or slightly above 12.

Aaron Cake

iTrader: (1)

That sounds a little low unless it is at idle. The cause is probably the underdrive. Also the FC gauge may not be accurate so check with a proper voltmeter.

arghx

iTrader: (3)

the stock voltmeter is flaky. Sometimes mine will read like 13.5ish with just about every electrical component turned off. Then when I check it with a multimeter it's reading maybe 14.3-14.5 . Sometimes I'll be sitting at a light with most stuff turned off and it will read 12 volts. I wouldn't trust it.

Syonyk

The stock voltmeter, while decent, isn't something I'd trust to diagnose my charging system. It's just not fine-grained enough to tell you what you need to know. A good digital voltmeter on the battery terminals will answer your questions.

You should be seeing ~14.7v with the engine at a decent RPM and not a whole lot of load. It will probably dip some under load, but with the FD alternator, you shouldn't be dropping below 14v or so at full load.

The dash gauge is useful for certain things - I can tell by the drop when the alternator is no longer able to power the full load (below 1500 RPM or so with all the devices on in the winter), and it's definitely able to tell me if the alternator goes out (though the idiot light glow should alert me as well).

-=Russ=-

RETed

Sorry, I think anything 14.5VDC is way too high.
I've run my FD alternator through two different VDO gauges and an HKS one, and they all read the same.
Highest I've seen is 14.0VDC.
At highest load at idle, it'll float slightly over 12.0VDC.
So the other guy's readings look right to me...


-Ted

NZConvertible

Gauges connected where? Put a DMM on the battery and you should see at least 14V, preferably ~14.5V.

RETed

Yes, they are coming off the battery.
Battery is relocated in the passenger side bin.
Well, the circuit is running through a relay, but it's close enough...


-Ted