[limited]

it would be easier to add additional grounds(from alt to engine). although the readings are borderline it should not cause any problems as is

[RyanGT]

I thought grounds were supposed to be .2? And they are .6-.7 from alt case to neg.

[limited]

Originally Posted by RyanGT I thought grounds were supposed to be .2? And they are .6-.7 from alt case to neg.

reality is more like .3v. you can improve your readings, what I am saying is .3v to .4v improvement won't fix a major problem.

If you are getting 14.4v at battery you are charging fine.

[RyanGT]

After car is warmed up I get 13.6 across battery. Cold it gets the full 14.4. Just the datalog reads low 13s when driving around. Which seems weird.

[RyanGT]

Went and cleaned (with a wire brush/electric cleaner/baking soda) the wires for the pos and neg, wasn't too bad but they are clean now! Also cleaned all the connections on the power block (fuse relay thing). Still same voltage across battery. And still same .6 voltage drop, on pos and neg.

[RyanGT]

before bed. So wraith can give some input!

[AFTERMATH02GT]

Fun Fact: "It takes power to make power, and for every 25 amps that an alternator produces, it saps about one horsepower from the engine to drive it."

Im not sure what type of power applications you are running in your car but in my last suv i had to upgrade to a H.O. Alternator (running 2k watts of bass) here's a interesting link: High Output Alternator

Another thing i did was upgrade to a deep cycle battery Optima yellow top: Optima Yellow Top Battery - Deep Cycle YellowTop Batteries
very noticeable gains my accessories would turn off when the base hit and the headlights would dim, no longer. Those optimas are spill proof, you can place them and almost any direction, faster recharging, very light ect.

The last thing you can do is upgrade the wire coming from the alternator directly to the positive on the battery no need to splice wires you can just put in a new piece 4awg or bigger i used 0 and a appropriate fuse and a neg strip same awg to a good ground or the engine block. on the ground i often had to remove the paint to get a good ground you can check for a good ground with a voltage reader.

Sorry if any of this is repeated i didn't read through all the pages.

[RyanGT]

Thats good info man! Im only running a 160. I don't have a real audio system (just stock stuff with a head unit). But i have a few things that take extra juice, like my intercooler and intercooler fan.

Right now i have the 0 fused gauge from the alt to power block. It was required. But the ground is still stock. And the power block to the battery is the stock size, which looks tiny... like a 6 gauge. Im thinking that i should upgrade the ground, and that wire. I just need to find the end links to use... The stock one has an awesome one that fills the whole power block terminal (big ass square piece).

All my grounds are bare metal, and i just cleaned them up again yesterday to make sure it wasn't the problem.

[wraitherx]

where are you seeing the .6 drop at? You have to keep in mind, depending on the DMM you are using that they can be within off a tad. escpecially the cheaper ones. Did you take it for a run and then log it to see if that drop was still present? As long as its not there you will be good to go just make sure that the drop isnt there and you should be alright. When you driving around the voltage is going to be lower because of multiple components running.

[limited]

If your looking at datalogs,what the ecm see's, it will be lower because of where the computer senses voltage. It is not directly hooked to battery and you have to account for resistance in that circuit also.

If you are seeing low to mid 13's under wot, regardless of what battery see's, you have plenty of voltage imo. you could be just chasing your tail

[wraitherx]

Originally Posted by limited If your looking at datalogs,what the ecm see's, it will be lower because of where the computer senses voltage. It is not directly hooked to battery and you have to account for resistance in that circuit also. If you are seeing low to mid 13's under wot, regardless of what battery see's, you have plenty of voltage imo. you could be just chasing your tail

exactly... the only thing that you need to worry about is that drop that i pointed out to you where it went down to 6v. the voltage should never drop below what the battery puts out (12v)

[RyanGT]

That could be sct error? You guys think I'm mostly ok then? Probably am. And what would cause than 6v voltage drop? Probably software error. How long did it last? If it was only a few cells that's like .1 seconds.

[RyanGT]

Voltage drop was measured at pos alt post, and both pos battrty and the relay/powerblock. Got same reading. And got same reading after a drive or letting it idle for a few mins.

[RyanGT]

So i increased the wire from the power block to the battery with a 1 gauge wire. And i did the Vaseline shiz everywhere. I am getting consistent 13.4-13.6 while driving normal/cruising/idle. But WOT drops to 12's constant. What do some of your guys logs show at WOT? Am i still chasing a ghost?

And i just replaced the ground with a 1 gauge wire also. Didn't help idle voltage at all. . Was a pain in the ass, i used the heavy wire from home depot. Shit is thick and doesnt bend well!

(have a log if you want to look at it)

[limited]

run a wire straight from alt to battery and see what results you have.

If you feel that you have an issue, I believe you will find it in a circuit other than the main charging circuit(battery cables etc) have you tried a different battery?

[RyanGT]

This has happened with old battery, that was my first suspect. Voltage is getting low. With lights on, driving around it is at 13.3. Im thinking voltage regulator?

I just don't understand how my car is frying alts over time. I don't put many miles on it. And it is the nice alt that the cobra guys at svt forums get made. To withstand high revs and such.

I have a log if you want to see the voltage in action. I emailed it to wrath. but haven't heard back in a week same with pm's.

[RyanGT]

Joe is also saying it is low voltage and causing a little injector mishap.

And when lights are on if i turn BAS to full, the car will go wacko lean (caps gauge at 20) misfires like crazy. And throws misfire codes on all 8 cylinders. If i don't have BAS at full and just half, this doesnt happen. I had lights on and turned bas on and seconds after this happened. Im guessing since low voltage it can't send the correct voltage and actually sends less.

[RyanGT]

before bed for the early guys. Think it is the regulator? Getting weird voltages and low voltages. But at idle it is ok warmed up at 13.6 (low but fine). Cold it gets 14.4 across battery. And warm with grounding to separate ground than thru battery it still gets 14.4. So it seems that alt has the voltage but not doing what it should?