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I need some help with charging my battery. Recently I noticed my battery is not getting charged. I have an alternator that has the positive terminal and the field wire going to the voltage regulator on the firewall. I thought the alternator was bad so I took it off and took it to the parts store and had it tested and they said it failed the test, so I bought a new one. Slapped it on today all excited to think I would have a charging mechanism for my battery again only to find out I'm not getting any help at the battery. When I put the volt meter on the battery, it showed 10.39 volts.

I recently installed a HEI distributor and put a tach in the truck. I don't know if maybe the way that is wired is fouling it up. The hot wire for the tach from the distributor is piggy backing on the wire coming from the ignition side of the voltage regulator on the firewall. On the voltage regulator, it says "do not ground." I don't think I have it grounded. It has a VR32 voltage regulator. Could it have gone bad and keep the battery from getting charged? My amp meter on the dash shows on the negative side when the truck is running. Anyone have any ideas? I have a 1949 Chevy pickup with 235 engine pretty much all stock.

12 volt system?
What alternator? Are you sure it requires an external voltage regulator?

Yes, 12 volts. It's a Duralast 7133 from Auto Zone.

If it is a stock 49, you shouldn't have an alternator.

Can you post up some pictures of what you have? I have a few suspicions, but I don't want to muddy the water with potential misinformation.

Or if you have the part number of the one you just got from the store, that would help.

One last thing to try: I suspect you are measuring the battery voltage with the engine idling. Most alternators need to be spinning at a minimum rpm to charge.

Try reving the engine up to 1,000rpm or so and check the battery voltage then.

Truck was converted to 12 volts with alternator and voltage regulator. Alternator has one lead and one field wire going to voltage regulator.

The only reason I stepped away from a generator and went with an alternator on my '50 truck was not because I wanted to get rid of the generator. It was because I had fits with regulators. I went with an alternator with internal regulator and have never looked back.

After doing some more research on this alternator, the website says it is not one wire compatible, but it also says it needs an external regulator. The attached pdf shows that there should be a wire going from the alternator to the F tab on the regulator. I have that currently and that is the way the previous alternator was wired. It also shows that it needs to be grounded. It is not grounded. Neither was the previous alternator. What size wire should I use for a ground wire and should I ground it to the frame or can I ground it to the engine?

RUN- - - -do not walk away from that style of alternator. When they were brand new in 1965 they were junk, and time hasn't made them any better. The external regulators give a truckload of problems and you need an idiot light or at least a 100 ohm resistor in the circuit to energize the alternator field circuit. Get a 10-SI type alternator with an internal regulator and a simple 2-wire exciter harness to make it work properly. I'm about 40 miles from Estill Springs- - - -get the right alternator and I'll be glad to help you wire it up.
Jerry

Thanks Jerry. I'm assuming I will need to rewire from what I currently have with the 10-SI alternator? I'm also assuming that I will no longer be using the ammeter. I may need my hand held on how to do all of this. Looking at all the 10-SI alternators on Amazon, I'm not even sure which one of those to buy.

Will this one work?

You probably don't need a 105 amp alternator. This is the one I used, as recommended by Bartamos. Works OK with original ammeter.

Alternator

Thanks. And how about the wiring? Right now I have the main wire to the battery lead and a smaller wire going from the F terminal on the alternator to the F terminal on the voltage regulator. I'm assuming I can do away with the wire going to the regulator. Does the alternator need to be grounded?

The alternator grounds through its case. So just make sure the mount is clean where the alternator touches it and where it touches the block.

Do you have a good frame->block ground wire already? If not, this would be a great time to add one.

Jerry. I have the 10-SI type alternator ordered and it should be here Thursday. I will need info on how to wire it, going from wiring with a regulator to this.

Thanks,
Darrell

The wiring harness shown in this Ebay ad has a diode built in to prevent engine run-on when the ignition is shut off. The red wire goes to any constant 12 volt source, such as the big terminal at the top of the starter, or the ammeter, etc. It can be connected to the charging output terminal of the alternator, but there's usually a slightly more steady voltage reference a few feet away from the alternator. The white wire is connected to any switched 12V connection, such as the ignition on/off terminal at the dash switch, or the ignition coil (+) terminal. The heavy charging current lead can be attached to the ammeter, the battery cable terminal at the starter, or directly to the battery + cable clamp.

www.ebay.com/itm/191103912421?

Jerry

I'm ready to do this conversion. My question is what do I do with the connections at the voltage regulator. A wiring diagram would be very helpful.. Thank you.