Hello, does anyone know where I can find the wiring schematics for the alternator? I look all around on google, couldn't find anything. I see a 3 pin connector, one is yellow with a black stripe, one is white, one is brown. I don't need to take it out, just tapping into some of the wires. Any help would be great.

 

https://cardiagn.com/2014-nissan-max...ir-manual-pdf/

 

thanks, any chance you'd know which part of this shows the alt wiring? I looked through it, couldn't find it

 

I'm gonna go out on a limb here and take a wild guess that it's the one labeled, "charging system".

 

Question, alternator should be pretty simple to wire up, why would you want wiring diagrams for that?

 

Great question... im wiring in a module to increase the voltage for my car audio application, need to know which is the C terminal wire, and which is the sense wire. Module allows it to bypass the PCM. I have a lithium battery which really needs to charge to 15+V, at 13.5-14V (PCM wont let it go higher) its operating at like 20% capacity, if that...causing a lot of headaches. New alt installed is like $700-800, so this module would help a TON

 

What module?

 

not a module i guess, its a voltage control **** https://brand-x-electrical.myshopify...ed-alternators

 

Your Lithium battery does not need to charge at 15+ volts. You're using LiFePo4 in 4S. Nominal voltage is 12.8. Your charging system voltage at 14V is right at the happy spot for that chemistry. Who told you you're only running 20%? And 20% of what? SoC? You don't need that regulator and in fact, you will damage your battery by using it.

 

Im running cmax, really wants to see 15.5-16

 

Ah, LiMn2O4. Carry on. Sorry for being presumptive!

You're still at around 70% SoC if you're charging at 14.5V. This is perfectly fine. Lion batteries don't like to be really full, or really dead. If you can keep them in the upper 25th percentile SoC you actually extend their charging cycle lifespan.

Are you running 45ah? 90ah?

 

Only 20ah, its very rare the car sees 14.4v though, usually floats around 13-14 (13-13.5 when its warmer out). My biggest issue is if i leave a door open for 10min with the car off, battery dies, cant let that happen again. The battery % isnt like taking 13.5/16 and saying thats 70%, at 13v its only using about 20% of its capability, so any power draw with the car off drains the batt real quick. Retested the cells after the discharge, theyre all good. This little "trick" can solve a lot of my problems...tired of staring at my voltage gauge to monitor when it drops. When the PCM brings it under 13.5, it drops like a rock when im bumpin hard....but at 14+ it holds solid all day. Im only runnin 3500w amp, plenty of car audio guys runnin 20ah off this power with no issues, but their voltage is 15+

 

You are correct in that you are at around a 20% SoC if you are charging at 13V. That means each cell is around 3.25V, which is too low for that chemistry. So yeah, you need to fix that!

What you are referring to when you bring up "20% capability" is State of Charge. I just did the math as cmax batteries run 4 cells in series in auto applications.

You might also want to test for a parasitic draw. You should be able to leave your car door open for 10 minutes no problemo without killing a cheapo flooded lead acid battery. Something else is wrong if you can't leave a door open for 10 min with 20ah of Lithium even if it IS only charged to 25%.

 

Yea i hear ya man, thats a wholllle other can of worms. The lead acid never had any issues draining. Just the lithium. My thinking was at 20% its like a 8ah battery, which would drain quickly id think,..?

 

I dunno. I'd have to look at it. Are you running the Cmax alone or in parallel with the under hood battery?

 

Alone, was told not to use lead acid with it....was going to do it and i stall an isolator, but this would be MUCH easier and cheaper

 

That's what I figured. So you're probably only having a good time when the alternator is rotating. Hope you get it sorted out!

 

For the most part yea. When its cold it idles at 14-14.4 so its fine. I dont play it standing still anyways so...... i appreciate all the help!

 

Wish I could help more! I don't know much about PCM controlled charging system on the 7th gens. I put a 7th gen motor in my 5th gen last year, but I threw a 270amp DC Power Inc. alternator on it before I dropped it in. I don't have a system yet, but my alternator hums along at 14.85 all day long. I've got 120ah of Yinlong LTO cells going in soon. Looking forward to NOT having your problems lol.

 

daaaaaaamn, doin it up! This alt is a ***** to get to, thats why i said F it and went lithium...THEN found out it was pcm controlled. 🤬

 

Hope this bypass works. Let us know when you get it in please?

 

Definitely will. Brand X is owned by Jonathan Patrick, he used to work for CES until recently

 

So far....not working :-( VERY disappointed. Waiting for Jonathan to reply to my emails. The 2 schematics i've had people pull for my car, don't match whats actually in my car in regards to the order the wires are in the ALT plug.

 

Hold up, I'm taking a shower. I'll get back to this after

 

ok, thanks

 

Just wanted to follow up man, sorry, don't want to drive the car until I figure this out.

 

To get an accurate schematic including vehicle options, you'd need to disclose a VIN# to get that information. Best source would be from Nissan itself if you have someone in service that can do that for you. Second best choice would be from ProDemand. Comparing ProDemand to actual dealerships diagrams and repair procedures are almost verbatim.

 

The FSM link I posted is all you need. Even with different options, these cars are all fundamentally the same. I guess I need some more info on what you're doing. Can you post the schematic for the bypass, or whatever device you're trying to install? I wired my 2014 alternator up to a 2003 engine harness. There's not much to it.

Let me know and sorry for the delayed response, I got caught up with the devil and disappeared for a couple days. I've got to get my demons under control.

 

no worries. I actually concluded the Mitchel schematic was not accurate, the one I got from Nissan was different (but accurate).

 

The Mitchel schematic is the diagram for the voltage **** device?

Also, and my brain is still a bit offline, but aren't the 7th gens pcm regulated? I know that my alternator is internally regulated, but I am not running a stock alt. And mine DOES have the ALT S (sense) lead. I'd have to dig through and check my documentation to remember how I did mine.

 

Or have you got it figured out now and I just didn't put that together lol

 

no no, they had the schematic for the alternator wires. I wired up the voltage ****, but as of now its not working :-(

 

It would be my guess that the output of the **** ties into the ALT S lead. I looked at the site again for the **** but didn't see any documentation for it and no pics of how many leads it has.

 

Guess I could have read this first (brain off, I told you):

From the site

"This is an voltage **** to replace diodes on internally regulated alternators with S or Sense Pins. The peak voltage will vary on manufacturer of the alternator-you have. Rating is based off the 14.8v pcm bypass regulator we sell and install in the denso (sic) based alternators we build. Some manufacturers will see 15.2-4v peak with a 14v-14.2v set point.

You will wire these to S, and then to ignition with a 5a fuse inline. There will be no individual instructions with the unit as every vehicle is different "

 

The ignition lead is just power for the device. Then you have set control for voltage.

 

Pretty confident thats what I did here.

 

DC the sense lead from the car! The sense lead should only be connected to the ****.

 

Isnt that what I did? The wire i showed at the end was spliced into the sense wire from the alt and goes directly to the ****. or are you saying I need to cut the sense wire?

 

Cut the sense wire (yellow and black, at 00:46 seconds in the video) after your splice! This is when your battery idiot light will come on.

 

ohhhhhhhhhhhhhhhhhhhhhhh ok, thats one thing I wasn't clear on based on the directions. Do I use the end coming from the alt, or the end going to the...whatever its going to?