charging problem help

[rebelcuda73]

Just finished withe the starter and ecu problems now after replacing all the parts the system is still not charging.I've replaced or checked all the parts in the system and even made sure to put in a grounding strap to the fire wall connected to the ecu bracket and bolted to the manifold.But checked with a meter and it's only showing 12.5 when it's running.Someone mentioned running a seperate wire from the + side of the alternator with a fusible link to the + side of the battery.Is this a good idea, pros and cons and is this what you need to do to solve the problem.Thanks Chris

[Moparal]

Do you have battery voltage going to the big thread end on the alternator?  It should be hot all the time. When the car is running is when the green and blue wire make it charge. The steering column wire harness plugs that comes out of the bottom and hooks to the dash harness, may have a bad connection. It can still run and start the car and not be able to charge if broken, melted or loose. This is a big common problem with a/c cars and also it happens on non a/c cars often enough

[rebelcuda73]

I will check what you have said!!I did run a wire from the + side of the alternator straight to the battery for a minute without the link and checked the voltage on the battery and it was charging with that wire at around 14.

[Moparal]

So if thats the case, it sounds like the charging system is working, but you have no 12v supply.  The battery hot wire goes to the starter, and the starter relay. A brown wire that is with the positive battery wire, goes to the silonoid. This wire is usually brown and bolts to the smaller terminal on the starter. That wire goes up to the starter relay on the fenderwall, it is a small connection on the relay to.  A fuseagle link wire comes from the firewall harness and also hooks to the starter relay. All of this supplies voltage to the starter and dash. At the junktion box under the dash, it hooks up to column then leads to the alt gauge too.

[ShelbyDogg]

Alternator goes into the car with a black wire. unplug that connector on the engine side and look at that male pin. see if it is discolored. it usually gets dirty and builds up resistance then smokes itself.    All of your charging current goes through this one little pin.  You might want to get a new male and female pins and recrimp them on this pair. 
 On the inside, that black wire goes to one side of your amp meter. Make sure that your amp meter studs and mount are tight. If those short out, your whole harness can start melting.

  The other pair that smoke is the RED wire that comes in from your battery, on the other big plug.  Yours is probably okay because you can still start and run the car. Check those male and female pins anyway.

[rebelcuda73]

I followed what you guys suggested and found the connectors to clean and intact.Still the system was not charging.A friend suggested to take the middle wire off the alternator and run a new wire from the alternator to the negative side of the battery.And now the system is charging at about 14.And after finding a vacum leak the car is idling and seems to be running better.I don't know if thats the right way to repair it but for now it works and I am only trying to get the car to go in and out of the garage so I can work on the 74 cuda which has its paint and body work already done.Although the 73 is far from done I have a problem with the distributor wobbling but I will put that problem in the right area.Thanks for the help guys!!

[ShelbyDogg]

I followed what you guys suggested and found the connectors to clean and intact.Still the system was not charging.A friend suggested to take the middle wire off the alternator and run a new wire from the alternator to the negative side of the battery.And now the system is charging at about 14.

  I don't know what you hooked up, but none of the 3 alternator wires should go to the negative post of the battery.

If it's working, great.  But I hope you didn't ground the green wire.

[rebelcuda73]

I guess thats not a good thing.The black wire is the main wire.Then I have the green wire at the top of the alternator and the red wire on the side closest to the engine.I did run the wire from the green wire postion with the green wire disconnected.I did not run it for long and its not permantently hooked up!!Any suggestions??? Thanks

[ShelbyDogg]

The alternator and regulator circuit is very simple.  Black wire is the main charging wire. Hook it straight to the battery (+) Positive terminal at the starter solenoid for testing. Use 2 fusible links side by side if you leave it, but your ammeter wont work.

Blue wire, (you said yours was red)  gets 12v when key is on (ign) is on one Field terminal and also goes to the center pin on the voltage regulator.  Check both with a test light for 12 with key on.

Green wire, goes from other Alt field terminal  to outside pin on voltage regulator. VOTAGE REGULATOR MUST BE GROUNDED!

The regulator varies the ground on the green wire to regulate the voltage. You were bypassing the regulator by grounding the green wire.  Check all your wires to make sure that you have a good connection at each end.   Once you have charge voltage at the main alternator wire and battery, start following it back with a voltmeter through the bulkhead connector then to the ampeter post. (black wire)

[rebelcuda73]

Thanks Rob I will check what you have said.I did spend so time checking the connections this past weekend with a ohm meter to make sure they were correct.I know that there was 12 volts on the black wire all the time and 12 volts when the engine ran on the other two.But I noticed you said that the blue wire would have voltage when you turn the key.So I will recheck with the voltage.I also removed the connection to the - battery with the green wire instead I grounded it to the engine and it still charges. Thanks Chris

[rebelcuda73]

I forgot to ask when you say the voltage regulator needs to be grounded isn't it grounded by being bolted to the firewall.I know that the new voltage regulator that I installed is painted but it is bolted to the firewall and I ran a seperate wire from the engine to the ecu where bolts into the firewall.And I had moved the negative battery wire from the water pump to the head bolt for better grounding!! Thanks Chris

[ShelbyDogg]

Yeah,

You're probably grounded then.  I also run a small wire from the engine, to the ECU, then to the voltage regulator. I also have nuts behind the firewall so I can crank down on all four bolts.   I would use a test light and voltmeter to test your wires.  I've learned in the past that an ohm meter will show you continuity but when it came time for the circuit to flow, it didn't. 

Moving the green wire from the - battery to ground, basically did nothing. You are still bypassing the voltage regulator which could lead to an overcharging condition. (that is if we are talking about the Green Field wire that is on the alternator)

You chould change your parts with a working car's parts just to eliminate a bad voltage regulator and alternator.

[rebelcuda73]

I will try adding the wires and using nuts and bolts to tighten down.The voltage regulator is new and the alternator was checked by the local auto zone on their machine. Thanks Chris