alternator not charging

[Ralph221]

I am new to this site and a barnyard mechanic. I am working on a MF135 gas Perkins that has had the generator removed and an alternator installed. I am trying to figure out why the alternator is not charging properly. The battery is acceptable at 12.4v. It temporarily drops to 10.8v during the start cycle. I have about a 3v line loss when running at 1200 RPM on the positive side. But I can't figure out why... I have no line loss on the negative side. I have cleaned and inspected all terminals. With all connections made, my battery reads between 12.5 & 12.8 volts at 1200RPM. y thought is it should read around 13.5v. The alternator is like new. With no wire connected to it, the "Batt" terminal on the alternator registers 15.7v when running at 1200 RPM.
The alternator is an Delco 63A system Integrated unit. # 2 on the alternator is wired to the ammeter and # 1 is wired in common to the Ignition switch, gas gauge, coil, and one side post of the starter solenoid. The opposing side of the ammeter is wired to the primary post of the starter that is in common with the positive post of the battery. any wire carrying a load is a number 10 or 12 gauge. The Battery cables are 1 gauge.
With the ignition switch ON I show a negative reading on my ammeter. When running I still show a negative reading and no positive reading regardless of RPM, the needle is at 0 (zero) when the switch is OFF.
Thanks for any help.
While I do not see one, I cannot assume there wasn't a diode placed in the line to the ignition stich, gauges etc.. There is no idiot light, unless I am the idiot. I am truly stumped.

Thanks
Ralph

 

[WranglerX]

Typically that style alternator is a one wire and it should connect directly to the positive post on battery..... Any other "connections" for what ever runs tractor should also be connected to positive post of battery....

Also if it were me, I would dump ammeter and put in a volt meter....

Dale

 

[Ralph221]

Thank you for the feed back. If it turns out to be a faulty alternator I will go with the single wire approach, I prefer to keep it the same to avoid unnecessary costs. Do you have a Delco part number for the single wire Alt?
Again thank you
Ralph

 

[lpakiz]

Another idea: with the engine off, check your resting battery voltage. Should be 12.2-12.6? Remember this number EXACTLY.
Then run a wire from the big alternator output terminal DIRECTLY to the positive battery terminal. This would bypass all other connectors and possible open circuits and the ammeter.
Fire it up, wide open and see if your running voltage is higher than your beginning (resting) voltage. If its higher, it is charging.
Oh, and make sure your belt is tight. With engine off and ignition shut off or disabled, pull on a fan blade and see if you can turn the fan without turning the engine. If the fan turns easily, you have a belt problem. When running wide open, the fan should make a distinct buzzing, whistling or whirring sound.

 

[woody]

I am new to this site and a barnyard mechanic. I am working on a MF135 gas Perkins that has had the generator removed and an alternator installed. I am trying to figure out why the alternator is not charging properly. The battery is acceptable at 12.4v. It temporarily drops to 10.8v during the start cycle. I have about a 3v line loss when running at 1200 RPM on the positive side. But I can't figure out why... I have no line loss on the negative side. I have cleaned and inspected all terminals. With all connections made, my battery reads between 12.5 & 12.8 volts at 1200RPM. y thought is it should read around 13.5v. The alternator is like new. With no wire connected to it, the "Batt" terminal on the alternator registers 15.7v when running at 1200 RPM.
The alternator is an Delco 63A system Integrated unit. # 2 on the alternator is wired to the ammeter and # 1 is wired in common to the Ignition switch, gas gauge, coil, and one side post of the starter solenoid. The opposing side of the ammeter is wired to the primary post of the starter that is in common with the positive post of the battery. any wire carrying a load is a number 10 or 12 gauge. The Battery cables are 1 gauge.
With the ignition switch ON I show a negative reading on my ammeter. When running I still show a negative reading and no positive reading regardless of RPM, the needle is at 0 (zero) when the switch is OFF.
Thanks for any help.
While I do not see one, I cannot assume there wasn't a diode placed in the line to the ignition stich, gauges etc.. There is no idiot light, unless I am the idiot. I am truly stumped.

Thanks
Ralph

I have a problem with the wire going to the positive post of the starter. move that wire to the positive post of the battery or the hot side of the solenoid.

 

[WranglerX]

Thank you for the feed back. If it turns out to be a faulty alternator I will go with the single wire approach, I prefer to keep it the same to avoid unnecessary costs. Do you have a Delco part number for the single wire Alt?
Again thank you
Ralph

The Delco 63A is a one wire alternator....

And generally the single wire goes directly to battery positive post or on starter solenoid where positive battery cable connects...

And as for dumping ammeter and going volt meter, I 'm not talking big bucks...

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Dale