battery wont charge
 

Full story:

After sometime my battery cable got a little loose. I saw the radio reset as i hit a bump (was at 14V after the bump). The next morning I tightened the terminals, I did not short anything (Very careful about this).

After tightening the terminals I started my car and drove to pep boys, I wanted to buy interior cleaner. Upon starting my vehicle my steering was stiff like there was no power steering (I didnt check voltage). Like an idiot, I was thinking "this feels great, real race car" and that I was going to come home soon anyways.

I picked up the cleaner and proceeded to go home. I lost all power, I looked at my voltage and it was at 12V dropping quick to 11V. I pulled over into a parking lot. The car wouldn't start. I went and got my juke to jump my 370z. After jumping it The car started again at 12V and quickly dropped again to 11V with no power. So I drove the juke to pepboys bought a new battery since I have no tow hook (BP V2 kit) and swapped the battery. The car ran normal but still only 12V but dropping slower this time probably due to a new battery.

I proceeded to troubleshoot. I checked all fuses and harnesses to see if it was attached properly. Everything checked out ok, i even swapped some fuses for no reason. I then bought a new fusable link from nissan and swapped it (by battery power terminal). The old fusible link was fine but I was just hoping for the best.

Ok so new battery, checked fuses, new fusible link, harness looks perfectly attached. There is no dirt or liquid anywhere on the alternator. I really couldn't believe it. So I bought a new alternator.

I swapped the alternator in a repair shop today and it still wont charge..

Looking online the alternator is controlled by the ECU? Am I right? (WTF)
I read all posts on google, the forums, g37 forms 350z forums, I cannot find anyone with a similar case.
The car runs perfect except the battery will not charge.

Now if you want to change the ECU you will have to get your key reprogrammed and a vin number put in the ECU and a whole bunch of other stuff.

I will be checking the harness tomorrow but whats the chances this thick stationary piece of wire just failed?

Is there anything else I should be looking at? I looked at the relays and fuses already. Everything is grounded.

I also read the repair manual for the 370z charging system (lots of NISSAN TECH only diagnostics). I seen a TSB stating that if you have a loose battery connection not to use accessories as it may damage your ECU...(serious? from a slightly loose connection).

Any help appreciated. Really missing the older cars when things were simple. Thanks.

You should be seeing around 14V with the engine running at high idle. If you are showing less than 13V, I suspect the alternator or its control circuit. A VOM may be all you need for troubleshooting.

You need to double check that the alternator is working.

Just because its NEW? Doesn't mean it can't fail.

simple test, while running disconnect the negative terminal, and see if it dies

If it does the alternators not working.

If you notice the cars idle rise your alternators working.

You should be close to 14 volts while running.

gonna resume tests soon. I am going to test the voltage by the alternators end. Its true the new alternator might be bad.

Im glad everyone thinks its a simple issue.

My thoughts are since the ecu tells the alternator to charge the battery depending on the power level, maybe there is something wrong with the communication between the regulator(built in the alternator) ecu and alternator to battery.

or maybe im just thinking too deep about the situation but swapping parts def is not working for me.

While it is possible that the ECM is to blame, I have not seen anyone else report that, so I'm assuming it is a rare occurrence.

My guess is that you have a wiring problem - something didn't get plugged in correctly, wire(s) cut/burnt, &c.

Next on my list is the battery; then the alternator.

I brought it to a shop. They said the ipdm will not send signal to the alternator. So i ordered one for $1000 from the dealer for them to fix it. Crazy. This cars about to be junk soon. Now what if its the harness.

Thanks for the assistance. Will update to keep this on record.