Alternator, Battery, Ground????

cracra · Post by **cracra** » 10 Jul 2018, 21:56

Hello to everyone out there. So I am a woman trying to figure out why my new alternator is not charging my battery. I have taken off the wire that connects to the back of the alternator and first I'd like to know what this wire is? Next I am wondering if the copper wiring that is suppose to be out of the casing? I hope I phrased that right. Please anyone help. Have a job interview in the morning and I need to try and figure this out.

Thank you

Post by **RickHaleParker** » 11 Jul 2018, 16:29

Year, model and engine?

cracra · Post by **cracra** » 12 Jul 2018, 01:39

1991 Volvo 940 turbo. okay please forgive me cause I don't know the exact name of these parts, i'll do my best to describe them though lol. So, I noticed there is a big wire that connects to the starter but then it goes to something else too, and i noticed that about an inch or more of the copper wire is unprotected from the red casing. And so I'm wondering if that could be shorting it out?

Thank you Rick, I appreciate your response. as I said I am a woman trying to fix this myself...

Post by **RickHaleParker** » 12 Jul 2018, 03:34

It sounds like you are looking at the battery cable, big and runs to the positive (+) side of the battery and the starter. The insulation (Red casing) is there to keep it from shorting. If the battery cable shorts out, the alternator will not charge the battery and it can burn out your alternator. A quick fix is to wrap the damaged insulation part with damaged insulation with about three layers of black electrical tape.

The long term fix is to replace any damaged cables or wires.

If it has been shorting out, there is a good chance the Battery cable is internally damaged also the wire to the alternator could be internally damaged, which would keep a good alternator from charging the battery.

The bigger wire on the back of the alternator carries the charging current from the alternator to the battery. If it is open, shorted or damaged there is none or insufficient charging current flowing to the battery.

Being a woman is is irrelevant, my sister can out diagnose a lot of guys when it comes to automotive repair, and don't forget mathematics and computer code done by women, put a man on the moon.

cracra · Post by **cracra** » 04 Aug 2018, 17:03

Thank you, and usually I am pretty good at diagnosing problems with cars but this one has me stumped. So, I just got back from auto parts store and there test said voltage regulator. However, I believe voltage regulator is on the back of alternator but guy from auto parts said no. And because I'm a women I feel like when i told him that is where the regulator is he didn't believe me. So, I've come home to double check to make sure I am correct. Also, he said regulator was $160 and new alternator only $140.. which ,makes no sense at all to me. Any thoughts??

lummert · Post by **lummert** » 04 Aug 2018, 17:11

There should be a ground cable connected from the alternator casing to the engine block.

Post by **jimmy57** » 04 Aug 2018, 17:12

There is a short ground wire from alternator to the engine or the alternator bracket. That alternator mounts with rubber bushings and the arm that holds it tight to belt is also rubber mounted. Since it is rubber mounted it will not make a circuit to charge without the red wire to battery cable @ starter and the ground wire both connected.

The voltage regulator is built onto the back of alternator. You should have the warring lights with the battery lamp lit when key is first turned on. The alternator and its voltage regulator need the light circuit working in order to charge properly. The wire for voltage regulator is a skinny red/white stripe wire (unless the harness has been repaired) and should be slid onto a blade terminal on back of alternator. If there are two blade terminals it should be on the one with "B+/61" stamped next to it, not the one marked "W" if that alternator even has the W terminal.

Post by **RickHaleParker** » 04 Aug 2018, 18:34