Voltage Regulator question

I have been having a problem lately keeping the battery charged. I turn the key on and the charge light comes on. I start the motor and the charge light goes out, as it should in normal operation.
But, after running a while the battery gets weak. Eventually it won't restart the engine unless I jump start it or put a charger on the battery for a few hours.

I will be checking all the connections for "clean, tight, and bright." I did do a recent tuneup. But other than that I haven't touched the electrical system.

My dad suggested I check the voltage regulator. How can I tell if I have an internal or external voltage regulator.

My way of testing an alternator has always been to start the engine and disconnect the battery and see if the engine keeps running. If not, the alternator is bad. I have recently learned that this is bad for the alternator. And it won't detect a weak alternator.

So where do I start.

Thanks.

Pooh Bear

Soundguy

Me? Iff'n I was suspect alternator problems, I carry the alternator into enny automobile parts store for a "FREE" test.

But based upon yer stated "having to recharge" the battery. I'd suspect yer BATTERY is DYING. I'd carry it into the same autoparts store for a "FREE" battery check. Batterys don't live forever in tractor service..... ..Dell

Since you already know how to use a VOM, here's a simple test that is not foolproof, but has never yet failed me.

Start the motor, and connect the VOM right at the battery terminals to read voltage. Let the meter settle to a steady reading. If it won't settle, you've already determined the regulator is probably bad.

Usually they do settle down, though, even with a bad regulator. Now, turn the lights on and off, rev the motor a little, and anything else you can think of to vary current flow within acceptable parameters.

Voltage hold steady or only vary slighlty? Regulator probably good. Voltage vary wildly? Regulator probably bad.

This is one of the reasons I always prefer a guage package on my vehicles; you can often troubleshoot from the driver's seat without dismantling a thing. With a little luck, you can also see trouble developing long before the idiot light comes on.

I've been reluctant to take my alternators to an auto parts store ever since the teenage girl who was helping me managed to blow one up on the stand. She wasn't hurt, thank God, and I got a free alternator out of the incident, but still...

I'm replacing the battery anyway.
I borrowed this battery 2 years ago from my Dad.
He wants it back for his trolling motor.
He said by Monday I have to get a new battery.

I'd like to upgrade my alternator to a 60+ amp model. Right now the only thing I run is the ignition system of the tractor. I don't have working headlights or other electrical stuff. But sometimes when I try to run my power inverter off the tractor the alternator can't keep up.

I thought the system could be tested without taking anything apart, using a VOM.
With the tractor off, a fully charged battery should read 12 to 12.5 volts. With the tractor running the voltage should read 14 to 16 volts. Am I right about this (or even close).

Thanks.

Pooh Bear

Pooh;

You're "right on" with your expected voltage readings.

Check the voltage right at the battery POSTS to rule out a poor connection somewhere keeping the full charging voltage of the alternator from reaching the battery.

Look at the photo of a 10SI; and compare it to what you have...

On most; the Delco Remy logo will be visible as seen on the lower area of endbell in the photo; but some have been rebuilt with generic "endbells" without the trademark on them.

That picture is the first time I have seen the main output wire being fed back into the VR. Usually that function is done internally (for the ones I have taken apart).

Thanks.

Pooh Bear

For even more accurate voltage control AT THE BATTERY the lead from the regulator's #2 terminal can be connected as close to the battery's (plus) terminal as possible... to the battery cable stud on the starter solenoid for example. Our tractors can get along just fine with the jumper at the alternator; vehicles with more complicated electronics use "remote voltage sensing".

Not that it is a BAD thing for our old tractors; either! I have set up some of my alternator conversions over the years with "remote voltage sensing".

For more information on remote voltage sensing; as well as "one-wire" vs. "three-wire" alternators; punch up the link below.

• remote voltage sensing.

After reading the info on battery charging, I think I'll remove the batteries from my vehicles when using an external charger in the future.