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Voltage regulator


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For those of you who still use a external voltage regulator what brands do you use and where do you get them? Are they all universal or car specific?


I got mine from oreilly http://m.oreillyauto.com/mt/www.oreillyauto.com/site/c/detail/IDI0/290133/02115.oap?year=1971&make=Nissan&model=510&vi=1209978&ck=Search_voltage+regulator_1209978_2567&keyword=voltage+regulator+


Instructions say for ford or Chevy so assuming their generic. Car doesn't charge tho that's y I want to kno which regulators do work before I start blaming different parts


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I got mine from Carguest.

they are made by Wells

They are half the size and solid state units. I had best luck with them.


Echlin Brand the worst.made in USA


I dont know How Gemeric they can be. They need the right connector to plug in to them.


I would pull the alternator out and have it cked.

most times when a volt reg goes out it overvoltages.above 14volts



find soemthing similar to this and you can watch it before it goes bad



OK I dialed it up on O rileys. and they look like the Jap made ones. If Japn they are Good. if USA they Suck and was alot more money about 5 years ago. for the mechanical type as thats what shown.


I know Carquest and mayeb autozone sells the solid state ones(made in USA by Wells)

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There are some generic voltage regulators, but Datsuns use a specific type since the wiring isn't the same as a Chevy. In fact, there are dozens of different factory Datsun regulators, though almost all I've found are ELECTRICALLY identical. The issue is there are 5 different connectors (square, rectangle, rectangle with ears, round, and a round-pin rectangle) and several different mounting designs. I'm using a 610 regulator in a 620 and it doesn't really fit since it had captured nuts on the regulator and the 620, they're supposed to be open holes. But I'd bought a box of a dozen or so brand-new, 1970s/80s vintage replacement regulators for dirt cheap and well, A) they work, and B ) it's not like I have a pristene engine compartment anyway.


If you're looking for a decent regulator look for a solid-state, transistorized one vs the mechanical spring and coil-based ones that were used originally.


The one in your link is a common '70-74 Datsun regulator, works in both 510s, 521s, and 620s. Has the rectangle flat-blade connector. The pic on Oreilly's shows the right kind. IDI is a generic aftermarket parts source, there's no guarantee who actually made the part. But before blaming the regulator, also be sure the alternator works AND the charge light is working. If the charge light doesn't come on with the ignition on (engine not running) then sometimes they never get a field and won't charge,

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@hainz- yeah the alternator is new reman 50amp (for 510 with ac) and I had autozone test it with their machine and it passed. As far as that link you showed me I have a similar one but my 510 doesn't have a cigarette lighter but thanks


@datsunholic- thanks for the info. Alternator is replaced and checked and I replaced the dash bulbs because it was burned out. That was the reason my car originally stopped charging maybe but at the time I had no idea and assumed the alternator.


Ok so I turn the ignition on and the chg light comes on, I start the engine and the chg light stays on also (why I thought it was the regulator). If I unplug the regulator and start the car the charge light goes away. Either way it doesn't charge I'm only reding 12.15 off the battery on a full charges battery.


One more thing. Previous owner didn't have a regulator and I see no indication of him going internally regulated, he just didn't use a regulator. I been driving it like that because I had no idea what one was so wat kinda damage do you think I did by not using one?


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'71 510s didn't have a 50A alternator option. 78-81 ones did- and they are internally regulated.


Unplugging the regulator made the light go out because the light is fed through it.


Having an external regulator connected with an internally regulated alternator will make the light stay on all the time. But... usually it still charges. Someone did that on my '74.


No regulator on an unregulated alternator will either not charge at all, or will charge at 20+ volts and boil batteries.

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guys, how should a regulator test be preformed, I found out that mine had stripped wires due to corrosion, I replaced it as well as the connector, I replaced the alt as well with a remade one, now after starting the car the lights at dash goes dim then suddenly off after that they light up again, I cleaned every ground or connection with sand paper, so wheres the problem?

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The alternator I got is http://www.autozone.com/autozone/parts/Duralast-Import-Alternator/1971-Nissan-Datsun-510/_/N-iq2o1Z93xme?itemIdentifier=334268_188706_10563_


It shows it external but if u think it might be my problem il swap it for a 35 amper. It's the only one they had in stock.


Il try some test I found searching thru these forums wen I get the time and try to narrow it down.



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Datsunaholic is very knowlegable.


But there is 50 amp external alt they are listed as a substitute. I run them in my set ups with a external volt reg.


Now Im not a mind reader on what you have . I have to go my the part number. My ext alternator look like Internal volt reg ones.

I can only tell the difference on the early 35ampers.



Now whats this?

One more thing. Previous owner didn't have a regulator and I see no indication of him going internally regulated, he just didn't use a regulator. I been driving it like that because I had no idea what one was so wat kinda damage do you think I did by not using one?


Well if theres no regulator then there should be 2 jumper wires where the reg plugs in to the connector. If not, I dont no what the MoFo was doing.



so your saying this car was driving ok for awhile when you had this. or you just bough this and drove it home?


its possible the when you turn the key on the alternator is not see 12volt on one wire of the T connector.

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I'm at work now so can't test anything hopefully tomaro


This is the one I pulled off



This is the one I put in



Their is no jumper wires just the lonely clip. looks like this




Iv had the car about a year and a half and never any real charging issues I noticed, but I never checked with a voltmeter wen it was "working". like I said I had no idea what a voltage regulator was at the time no other car I owned had one.

I daily drove it for a while, only thing I replaced was the distributor. It had been upgraded to matchbox style and hopefully that was done right as well. I don't think it has anything to do with it but engine has been swapped to l18 by previous owner


The day I suspected my alternator of failing I was driving home and noticed the lights getting dim, then went my temp gauge and gas gauge. Wen I finally got home it basically just died no more juice left in the battery.

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OK. The 50A alternators are commonly swapped, they just weren't stock in a 510. At least, not from the factory. Dealer add-on, possibly. There are 50A external reg alternators, as they were an option on 620s, 610s, 710s, 200SXs, B210s, etc through '77. After that everything was internally regulated.


That alternator with the "SL" plug? That's an INTERNALLY regulated alternator. Exernal ones, the plug is labelled "FN".

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you have to do the above for a Internal reg alternator. look at the drawing. Make 2 jumper wires with the male blade connectors



If you have a External volt reg alternator , then you buy the square volt reg can and plug it in to thr pin pin connector

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hainz I checked my wiring harness at the voltage regulator connector, it seems everything is fine except the IG wire, when the key is off it gives 0V when the key is on engine not running it gives 11.4V - 11.6V less than 12 volts, I'm trying to find if there is a voltage drop somewhere thats making this, but I have no Idea where does the wire go to? does it go to a fuse or a relay, some tips well be appreciated

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OK hainz, I set a side the darn voltage regulator (MADE IN TAIWAN) and got a japan one, there was a difference in the connector type so I took the Taiwan connector and soldered it to the japaneas one (the japanease one had the wiring code written on the box :))

I started the car and waited a bit then checked the battary voltage to see it got higher than before, so I assume its charging, problem is that when I check with the multimeter on both the battary positive and negative I see the voltage not stable on a single reading; it just goes around certain values again and again and again, is this related to the fact that the contact points in the regulator are turned on and off? or should it be a one single value, I raised the rpm and found that the voltage raised from 13.7 to 14.2, didn't go higher in the rpm though, when unhooking the negative bat post the car seems to be more energetic and doesn't stall on me.

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I raised the rpm and found that the voltage raised from 13.7 to 14.2,


That sounds right.


The commeon later 510 volts regs are the square type connector like on your car.

Very early 510 had a different type I believe.(been good to save that volt reg also for the early 510 guys)



as for swapping wires as you did. I found out once that the color codes were correct on a volt reg I had but they didnt match the color code to the engine harness as they should.

You pysically have to see where the wires go. For you it would be harder as you said one connector is different than the other. But it soulds like you got it right.


always buy a spare ,esp for trouble shooting or if you find them for 25$ buy them up


Dont be unhooking the batter cables anymore to do this ck.


as for the volt being stesdy it should be steady. Maybe its ok you just looking at the last digit of the volt meter that you dont need to look at. longe as its above 13 volts with nothing on call it good. Rev it up and it stays under say 14.2 14.5 I would call it good.


if you got old cables .good time to change them out.


But I have pope the solid state volt regs when not connecting the cable down nice and tight. What happens I get 15 volts at idle and then load it down with heater and headlights and still reads 15volts.

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I checked the wires and where they go

A. BLACK --> ground

B. WHITE --> BAT on alt

C. WHITE with BLACK strip --> Field

D. YELLOW --> neutral

E. BLACK with WHITE strip --> IG wire

same to what the regulator box says.

as for the steady voltage; I'm not talking about the last digit, I'm talking about the whole voltage going up and down in an intervals of say a second, the numbers I've seen were 3.0V 7.0V 12.4V 13.4V 14.2V(when revving up), there is one thing that I didn't hook when I installed the japanese regulator, there was a bullet type connector connected to a capacitor to the original regulator, but I didn't hook it this time, the capacitor wire grounds with the chassis and the other terminal connects to a wire going with the Field wire(WB), perhaps it functions as smother for the output voltage, so it won't fall too much; if thats the case then that makes sense, as the voltage I'm seeing on battery is alternating in positive values, since this is mechanical it take time to recharge and discharge, so a cap would work as memory for voltage. :P physics :)

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Yes that is correct what you have

I dont have a fucking clue why tha charges up like you say from 3 to 14.2 volts.


Last time I seen soemthing close to this was a Internal Volt reg alternaot was installed in a 510 but the external volt reg was still on also.


I dont have a capcitor ,far as i know a Cap passes AC but blocks DC voltage.



If this was me I would swap out another alternator or VR as I have spares. But Im familiar with my car as I had it for years and know it. Your I would be partially guessing.


I would be winging it if I said a diaode was bad. Unless I had access to a O scop to ck out the Sine wave on it. Like a Pulasated DC. KInda like a Generator. once you get going fast enough you just can see the it .



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It's easy to check for AC voltage (shorted diode). Switch your multimeter to AC. It should read zero. If it reads anything over 3-4V AC, you have an unrectified generator.


I don't know why it would read as low as 3V- the battery should at least keep the voltage at 12V (ish). If you're testing with the battery disconnected, well, you'll never get a GOOD reading because the battery provides the smoothing (it's a big voltage spike damper). Plus you're doing the alternator and the regulator no favors. It's a good way to blow out the solid-state elements. If it's jumping around that's just loose connections.

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datsunaholic, your right; I never had the thought of using the ac read outs on the DMM, and I'm probably guessing it has to do with the wiring, the fusebox is shit all corroded and dirty, couldn't find a replacement for it so I tried to get my hands on datsun 720 fuse box new unit (its kind of the same), sales man answers: "ALL SOLD AND WE'RE NOT ORDERING ANY" . bought a universal set of fuseboxes that needs wiring, gonna crimp them to original harness(new ends), but still facing trouble with power buses in original fuse box; can I use a butt connector to connect the large gauge to the small fry wires batched in the other hole?

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  • 4 years later...

Make sure battery terminals and cable ends are clean and tight.

Make sure there is a wire from the negative cable to the body sheet metal or make one.

Make sure the alternator plug is in and secure, ground (Black) wire and the White/Red stripe power output wires are secure and tight.

Make sure fan belt is tight.

Does the charge light come on or glow????




Read across the battery terminals as this is what it's keeping charged.


12.6... fully charged engine off


14.0 to 14.6 ...... engine idling and alternator charging properly


Turn on headlamps and heater for load test.... may drop below 13 volts red charge lamp may flicker on or dimly on but should turn off and voltage climb to 14s when revved up.




Borrow a known good battery and see if different.

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