To see how many amps the system is pulling. You should put an amp clamp on the positive battery cable. And run the car for a while.

Update on my issue. Starter and alternator have been replaced. Car starts. Runs great at wide open throttle but still misfires and is only giving me mid to high 13’s for voltage. Found two codes, that don’t throw check engine lights, that lead to a sensor in the negative wire coming off the battery that apparently controls voltage to the alternator. I’ve never even heard of this. So that’s what I’m digging into next. These cars have too many sensors lol


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Ground..... it's always ground.... :bowrofl:

The alternator has to have power from the fuse box for field power, which also means, a ground back to the battery. You may have to run that wire(s) and check for burnt spots that might cause intermittent shorts. You're on the right track. :tup:

It's impossible to say that too many times!

And it's always the hardest problem to find (as you have discovered) Good luck; make sure to keep updating this thread.

Update on the misfiring and low voltage situation.

I did a deep scan on the car and found 2 codes related to the battery current sensor. I’ve never heard of this thing but it’s a sensor in the negative battery terminal wire that essentially communicates the load to the ECU and then the ECU tells the alternator how much voltage to pump out. Well my car is missing that sensor. I ordered a new one and am expecting it in any day now. After reading up on the sensor all the symptoms I’ve been having match up to everything that this sensor controls, even down to the power draw when the cars off. My only concern is I’ve had the car for 3 years and it’s been boosted for 30k miles, I’ve never taken this sensor out myself why did it wait until the last 8 months to get this bad a reveal itself?? Hoping this wire is my problem


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:icon14:

Just a guess but you may have been doing a small amount of damage each time you operated the car. A little damage here; a little damage there; then poof.

It’s possible. It really showed a few months after I upped my power levels and got the car re-tuned. I can see the sensor slowly going bad and then getting to this point but the thing is 100% missing lol. It’s a mystery I wish I didn’t have to solve haha


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I suspect that whoever did the original build, swapped out the battery ground cable because it either got smoked or it was a false attempt at saving weight. I've read way too many build threads where people put microscopic batteries in the car to 'save weight' and then wonder how come their battery cables get fried....:eek:

That’s almost what I’m thinking too. Originally AAM did the install at their shop. I swapped the engine about a year ago (not at AAM) and as we were going through everything we found a few corners that were cut and I wouldn’t be surprised if the sensor was giving them issues or if it got lost during the install and they just put it to the side. Regardless it’s being put back on when ever usps decides they want to give me my package and we’ll see what the voltage reads after. Fingers crossed!


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