cblake3

iTrader: (2)

I was going to run an extra line from the positive post on the alternator to the positive post on the battery.
From what I have read, this will slightly help with a voltage drop (1volt or so) from the Alt to the Batt.
I have 10 gauge wire. Is this big enough?
Should I run a fuse in line? If so, what size?

Rxmfn7

iTrader: (4)

I ran 10G wire on mine, it seems to be enough. I dont think you need to run a fuse (I didnt), but you may want to get someones elses opinion on this, as I am electrically retarded.

cblake3

iTrader: (2)

did you notice any difference with the new line in place?

Rxmfn7

iTrader: (4)

Well, not yet cuz my charging system is still fubar'd, but I have heard from many people that it does significantly improve the charge at idle.

J-Rat

iTrader: (2)

yeah, you can run it direct from the alternator to the battery, 10 Ga is plenty big enough, and no need for a fuse.

It ups the voltage a bit, but it wasnt enough for me, so I went to the FD alternator.

rx7_ragtop

Hmmmm... bigger (lower numerically) would be better.

Brad

cblake3

iTrader: (2)

I have been pondering the 3rd gen alternator for about a year, but I don't have the extra $200 for one at this point.
Tell me this, I am seeing 14.4 at the alt output, but low 13's at idle at the positive post on the battery. I am seeing high 12's with the headlights on.
Bad battery???

J-Rat

iTrader: (2)

yeah, but 10 ga is sufficient. Its actually about the size of the pre-existing one.

J-Rat

iTrader: (2)

Actually, those numbers arent all that bad...

KNONFS

iTrader: (14)

If you get 14.4V @ the alt (with everything off, and at idle) you should get VERY similar numbers at the Batt. You should not loose 1 volt thru the cable between the alt and the batt..........

BTW - Make sure that the batt terminals are clean, and also the batt poles........

cblake3

iTrader: (2)

Besides dirty terminals (they are spotless), what else would case such a loss

DriftinJim

iTrader: (24)

Add an extra ground strap from the negative battery terminal to the frame. You can buy a pre-crimped one at wal-mart for like $3-4 and obviously at an auto parts store. Be sure to measure the needed length 1st so you don't get a lot of excess.

cblake3

iTrader: (2)

I have 2 10 gauge wires coming off of the - battery post to the chassis. Too small??
I also have about 3 additional ground wires going from the block to the chassis. All are 10 gauge.
These helped with the 3800 stumble, but not completely.
Any other suggetions??

KNONFS

iTrader: (14)

2 10G wire is equal to 1 8G wire, and that is awfully small. Run a 4G wire for the ground, however I don't think the ground is your problem between the alt and the batt.

The cable that runs from the bat to the alt might be corroded, try using an extra 10G wire in between them and measure it up.........

Let us know!

presetlimits

im having the same probs, when driving the car is fine, but at idle the volts seem to drop way too much. but if i push the gas just a little say up too 1000rpms..then the volts are fine..i have the fd alternator as well

J-Rat

iTrader: (2)

I posted my theory on that...being that the FD pulley had a REALLY small diameter, so it spun faster at idle. With the FC pulley on it, it spins a little slower at idle and the volts fall..

Rat

presetlimits

will yours fall to like 12.5-13 at idle with the headlights and efan on?

schexy1

your alternator will not give you full voltage at idle under with a load(lights on). There should not be a voltage drop at any point in the system. If there is then your wires are the problem. You could run another wire but I would just replace the factory one with 4awg.

J-Rat

iTrader: (2)

I get a slight drop at idle with the e-fan and the headlights..Maybe its time to run a bigger wire?

Rat