Searched CHARGING ISSUES...

[justjack]

Hi all i looked around and saw some posts from the past about charging issues and tried everything they recommended and cant figure it out! i got a 1992 240sx coupe, my problem is my charging system is not working. i replaced the alternator which i got bench tested and is good, and new battery, and after i got it all hooked up the alternator is not putting out any juice. i then started looking around tore in to the harness and saw their was a wire not hookedup so i connected it and still nada. my charge lamp in my dash came on and off when my buddies where messing around with the alternator but does not stay on constantly... the battery is reading 11.8 volts when running and the alternator is putting out nothing, like its not getting electricity. i know im not the most descriptive but i dont know alot about electrical. any ideas would be great im thinking of getting a newish engine harness and just swap in a new one and hope it fixes it....

[OutToWinPAHC]

that small harness wont cause that.

An alternator is an AC motor spun backwards to produce AC voltage, which is then rectified and regulated from 12-14.5VDC. You only need to good connections for it to work. One the wire , positive, that goes back to the battery. And the other is a good clean mating surface to the block which is grounded. Check the engine ground and replace if needed, then with some sand paper or a wire brush check where the alt mounts to the engine.

[OutToWinPAHC]

Oh and the EL section of the FSM has troubleshoot tips

[zachattack_5491]

The main part of the charging system is the white wire that connects the battery and the alternator, and the alternator ground. There's some stuff that runs inside the cabin but it's not really the important. Also, check the alternator fuse.

[justjack]

i read up on the el part of the fsm and i dont see anything about trouble shooting... any ideas guys? this thing is killin me!

[OutToWinPAHC]

I think we told you, check the two connections, check the fuse, check the battery, re-test the alt

[zachattack_5491]

There may not be a guide for troubleshooting but you can read the wiring diagram and see that the system goes alternator >> connector >> fuse >> battery. So if you haven't be cutting the wires and it looks good visually, you should check each of those connections visually and with a multimeter if possible, then make sure the ground is solid. Once you're done with that I'm sure you will find some new information that will help solve your problem.

/guide to troubleshooting with no troubleshooting guide

[Armstec_S13]

check the connector that plugs into the top of the alternator and make sure there's no corrosion and make sure the ground is connected to the back of that alternator and also the positive wire is connected to the back of the alternator, all else fails check the fuse