Datsun Roadster Forum-311s.org

Alright you have a factory alternator and an aftermarket voltage regulator. The thing to do is get both the alternator and regulator tested. If they test good it’s likely that you have a problem in the wiring harness or the AMP meter.
Dave

Thanks for confirming, Dave. The manger at auto zone who tested my battery said she could test the alternator for me too so I’ll stop by there tomorrow with the car and see what the test reports.

I thought that the factory alternator was the wire kind, but there’s only a single wire coming out of mine (and no ground). Does that make sense?

Wonder if these things are worth a damn? Seems to be plenty of happy campers based on the reviews, that or blissfully ignorant. Of course a working cigarette lighter socket is required.

12V Plug in Car Battery and Charging System Tester, Test Battery Condition & Alternator Charging (LCD Display)

https://www.amazon.com/gp/aw/d/B07422ZP ... asin_title

It’s just a volt meter and unless you have another voltmeter, you really can’t be sure of its accuracy.

Peace, Pat

I have been using this type of tester for well over twenty years. It’s cheap, dependable, and easy to use.

theunz wrote: Wed Aug 09, 2023 7:55 am I have been using this type of tester for well over twenty years. It’s cheap, dependable, and easy to use.

But yikes on a car with an I C -loading it with the knob ,
Take it to the parts store

redroadster wrote: Wed Aug 09, 2023 8:28 am

theunz wrote: Wed Aug 09, 2023 7:55 am I have been using this type of tester for well over twenty years. It’s cheap, dependable, and easy to use.

But yikes on a car with an I C -loading it with the knob ,
Take it to the parts store

You simply disconnect the battery cables and there is nothing to hurt no matter how complex your electrical system is.

david premo wrote: Tue Aug 08, 2023 7:31 pm Alright you have a factory alternator and an aftermarket voltage regulator. The thing to do is get both the alternator and regulator tested. If they test good it’s likely that you have a problem in the wiring harness or the AMP meter.
Dave

I stopped by autozone with the car this afternoon and they hooked their tester up. Battery reported good and it had me start the car. It reported that the starter was bad.

I've started looking into the gear reduction replacement starter. I clearly have no idea what the starter is. I thought it was this: https://i.imgur.com/umXD8HK.jpg (What is the thing I circled?)

Does replacing the starter sound reasonable as the cause of why I'm not seeing my battery charge?

The person at autozone also suggested I replace the terminals on my battery cables since the negative terminal I have doesn't fully tighten and they are both pretty beat up, so I grabbed a new pair and will replace them tomorrow.

eab wrote: Wed Aug 09, 2023 10:51 pm

david premo wrote: Tue Aug 08, 2023 7:31 pm Alright you have a factory alternator and an aftermarket voltage regulator. The thing to do is get both the alternator and regulator tested. If they test good it’s likely that you have a problem in the wiring harness or the AMP meter.
Dave

I stopped by autozone with the car this afternoon and they hooked their tester up. Battery reported good and it had me start the car. It reported that the starter was bad.

I've started looking into the gear reduction replacement starter. I clearly have no idea what the starter is. I thought it was this: https://i.imgur.com/umXD8HK.jpg (What is the thing I circled?)

Does replacing the starter sound reasonable as the cause of why I'm not seeing my battery charge?

The person at autozone also suggested I replace the terminals on my battery cables since the negative terminal I have doesn't fully tighten and they are both pretty beat up, so I grabbed a new pair and will replace them tomorrow.

No that's the coil. It provides the electricity to the Distributor > Spark Plugs. The starter can cause battery drain, but is not normally the prime suspect for Battery drain. BUT IT CAN. The Starter is located at the bottom of the engine on the opposite side of the car from the Coil. See the Brake and Clutch Master Cylinder mounted to the firewall, the starter is down below them.

Here is a thread that might be of help and includes a photo of the starter. At a minimum you will need a 3/8 or 1/2 inch Ratchet, extentions and a wobble joint. From reading up on this problem. It may be that the solenoid portion of the Starter is the culprit. Smarter people than myself can probably tell you if it's possible to just swap that out instead of the entire Starter and if it can be done without removing the Starter from the car.

viewtopic.php?t=14424

Here is the gear reduction starter at about the best price you will find.

https://www.ebay.com/itm/185848123221?m ... media=COPY

The starter can not cause your charging problems. Did they saw what was supposedly the problem with the starter?

Take the car to another parts house for a second opinion.

As we have seen, poor grounds can cause a myriad of problems. Corrosion or loose connections will make starting problematic so it won't hurt to start with cleaning connections at the battery and starter, checking for ground straps (do they exist?) and cleaning connections there. A poor connection will act like a weak or drained battery (slow turning or a complete disconnect). Be aware that the positive cable connected to the battery (and then the starter) is "hot", so don't touch it to metal while connected to the battery except to where is supposed to go (the starter) or it will spark. Spark next to fuel can cause a fire or explosion. If you put a wrench on the positive cable where it connects to the starter and then contact metal with the wrench it will spark... I still have a 13mm wrench with a notch in it from when it tried to weld itself to a ring on my hand when I touched it to the exhaust header and the starter (when I was a naive 16yr old) and the battery wasn't disconnected... lesson learned.
Respect the electrical system and battery. Batteries can explode, they can be overcharged and leak acid, a spark can cause the gasses venting from them to explode... just be aware. Never put the negative cable from a jumper cable onto the negative post on the battery... ground it to a proper bolt on the car or engine because it can (rarely) cause a spark and explosion. I met a tow truck driver that had facial scars from having done that and causing the battery to explode in his face.

A little clarification on Greg’s post. The positive battery cable will only be “hot” when the negative cable is connected to the battery. Once the negative cable is disconnected you can touch the end of the positive cable to anything EXCEPT the negative terminal of the battery.
As for the starter… it is possible that only the solenoid is bad, but as cheap as the whole starter is with its new solenoid you are far better off to just replace them both. Not to mention that trying to swap out solenoids while the starter is still on the car could be a real bit*h.

One way to test the alt is leave the belt kinda loose its hard to turn a good charging alt it will squeal after starting of its charging good .
my 4g63 alt belt squeals like crazy on start up , put a cheaper belt on it its tight though
The alt neg side/ground thru the neg cable. At the block and thru the field / regulator
It's best to say neg not ground as its way different that AC ground .
pull your regulator cap off , and with it running lift the contact that fully charges the field ( for a short time 4' 5 sec ) and or see if the contacts are teetering up and down DO
Not try to adjust the contacts it very very presice
If you do not want to pull the alt to take to test.