Over charging altenator

[75Bulletside]

Hi guys. Ive got a 1975 620 with an l20b in it. the alternator is charging at 22.97 volts at idle. it has an external regulator. should i start with replacing that. and if that doesn't fix it what should i look towards next???

 

Any input and help on this matter would be greatly appreciated. its my DD and i need to get her back to life and on the road again.

[Skib]

yes.

 

the regulator isnt doing its job, replace the external regulator.

 

stop running it until you do. the over charge can and will damage your system.

[Boaty]

And by damage your 'system', Skib means you can overcharge your battery and it can blow up. You're close to that if you end up with battery acid spewing everywhere.. gel-cells expand and then go poof everywhere. The smell is horribad.

 

Take this opportunity to do the Saturn alternator swap and never worry about it again (and enjoy some more juice and readily available parts). :)

Lots of info on that here on Ratsun.

 

Oh - I see you're in Grants Pass. So am I. I can help you out with it if you go that route, if you'd like. It's really simple. I work graveyard out in Murphy at the store, though. So it'd have to wait for a free weekend.

[DanielC]

I would clean the battery cables first. Check the voltage on the battery terminals, not on the cable clamp.

Reality is, the voltage regulator probably is not good, but if you are replacing anything in the charging system, having clean battery terminals is a good thing.

[thisismatt]

Boaty - isn't the KA24E hardbody alt a better alternative to the Saturn alt as far as fitment is concerned? I tried the Saturn alt in my 521 and the fitment was pretty bad (very limited range of movement due to the idler arm, and the top alt mount is in the wrong place on the Saturn alt). Plus you have to cobble together a janky adjustment arm/turnbuckle. I ended up doing an Eagle Talon alt swap that had it's own issue, but the fitment was a lot better...

[75Bulletside]

The battery and battery cables are new. Voltage on the battery is 12.94 with out the car running. While I start it it drops to about 8 volts. Which indicates that I have already discharged the battery by overcharging. At this point I was just wondering if i could get away with just doing a voltage regulator until I've got money to swap alternator's out.

 

Boaty- I would appreciate any help whenever you have free time. Anybody have any idea about the pricing on A- the voltage regulator. B- A new/bigger alternator?

 

Thanks for the quick replays and all the help :)

[ggzilla]

22V can burn up the wiring harness and other parts of your Datsun.

[Dawa]

i parked my car friday and went back to it 6 hours later and it wouldnt start (not enough juice.)

figured i mustve left an accessory on or had a short somewhere...

i left the battery on a tender overnight, and meanwhile researched 'lowest voltage to start car' or something along those lines.

saturday:

installed the battery, and it started up. took that chance to install my voltmeter, as well as fixed a wire that i thought might

be causing the short.

 

one of the things i learned while researching 'lowest voltage to start car' or whatever, was that most cars drop to 8vs when

you try to start them (i can attest to this now that i have my volt meter installed.)

 

also, another possible reason for my depleted battery couldve been that im now running a stereo AND had the lights on right

before i parked it. i have an alternator upgrade in my future, once i REread up on which one is 'easiest'