Instrument voltage

[crabbyone]

When did Datsun stop using the "voltage regulator" on the fuel and water temp gauges in the trucks? Also, when did Datsun switch from 6 volt electrical systems to 12 volt? And, did Datsun stay 6 volt longer for the Japanese domestic market? Just wondering....but if the fuel and water temperature gauges in my 520 are leftover from a full 6 volt system, why couldn't I purchase an aftermarket hotrod unit to replace the irritating, sporadically uncooperative piece of male bovine organic byproduct on my instrument panel? Well?

 

Crabby

[banzai510(hainz)]

IM not a 520 expert but i thought they were 12volt system

 

However the voltage reg in the instrument panel uses very little voltage for the gauge to work. I think if you put 6-9volts on that volt reg the gauges will read full/hot. I have done this once. But hs been awhile

[ppeters914]

Just an FYI that I'm currently writing a how-to with pics. In the meantime;

 

- 520 is 12V.

- With ignition on, short the sender wire to ground. Gauge should go to full (gas) or high (water temp).

- If only one gauge is flakey, the instrument voltage regular is probably -NOT- the problem.

- Dunno exactly when the instrument voltage regular went away, but they're definitely there through 1971.

 

Nothing stopping you from replacing the stock gauges. Not rocket science, just time and money. You're lucky with a truck in that you can hang aftermarket gauges without 'em looking like crap. No clean way on a 411. :(

Edited October 19, 2008 by ppeters914

[crabbyone]

I am well aware that my 520 is 12 volt.I have been dealing with Datsuns for almost 40 years....damn!!!! No feelings stepped on though. Was more of a rhetorical question about why the two gauges need the reduction in voltage. I pulled the panel out and cleaned and tightened the miserable little thing. Gas gauge actually reads some....for a while. Actually, I am pondering a full panel replacement. I think Classic has a line of gauges with the military aircraft fascias. Look pretty neat, I think.

[datzenmike]

The 620s had the voltage regulators too. It provides an on/off pulse of 8 volts that ignores the 12 to 14.8 volt charging fluctuations normally present in the charging system. The 720's up to 86.5 have one built into the dash just to the left of center by the clock. I've used 620 and 720 gas tanks and swapped oil pressure senders and they read the same, so I would guess the regulators work the same too.

[ppeters914]

FWIW, I've found that the instrument voltage regulators were used at least until the early 90's. Our older Dattos use the mechanical one.

 

Back of gauge panel

 

 

Back of gauge panel with voltage regulator removed

 

 

Close-up of where voltage regulator connects

 

 

Here's several pics of the little beastie itself as used on 311/410/411/510/520/521 and who knows what else

 

 

 

 

TESTING THE GAUGE VOLTAGE REGULATOR

 

Connect an analog multimeter or just a dash light to the case and the non-IGN terminal of the voltage regular. A digitial multimeter will work, but it'll kinda go spastic.

 

IMPORTANT!!! You must connect the meter or light first before the 12VDC.

 

Connect 12VDC to the case and the IGN terminal of the voltage regulator.

 

If the voltage regulator is working, you will see the meter bounce from 12VDC to zero and back regularly. If it only bounces once, you may have the 12VDC leads reversed. If nothing, the voltage regulator most likely needs replacing. Last I heard, they were still in stock ~$20.

Edited October 28, 2008 by ppeters914

[Pacific coast Datsun]

Pete TY for the pics/info. My 620 has irratic gas & temp gauges too & im hoping its just the regulator. I want at least the gas gauge to work..i can install an aftermarket temp gauge later [have a few already].

[crabbyone]

x2 to ppeters for the info. I took mine out, because I'm nosy, didn't see anything that interested me in the least, and reinstalled it. However, before I plugged it back in, I gave the connectors on the panel a slight squeeze to make the connection a little tighter. Yes my gas gauge is now reading accurately for the first time in years. I figure most of these regulators have been in place a long time, and a little more metal to metal contact can't hurt. Ain't dumb luck wonderful?

 

Crabby

[MikeRL411]

The Voltage Regulator for the 411 and 510 are "almost" identical, you just bend the tab of the 510 and it fits the 411 instrument panel very well. If mine ever fails again and I can't dig up a 410/411 or 510 regulator I'm going to wire up a 9 volt zener diode and resistor and says "to hell with your mechanical system".

[MikeRL411]

Using USA designations, voltage regulators of various types were used in the

L60 Nissan Patrol, PL411 1300cc Bluebird sedan, RL411 Bluebird 1600 Super Sport Sedan, PL510 sedan and coupe, L520 and L521 1300cc pickups, PL521 1600cc pickup, SPL311 1600cc FairLady sport car, SRL311 2 liter FairLady sport car.

 

Surprisingly no Voltage Regulator was used in the PL410 1300cc Bluebird Sedan despite its similarity to the 411s. The SPL310 1500 FairLady sport car, LB110 1200 sedan and L320 1200cc pickup also had no voltage regulator.

 

Above based on a magnifying glass review of schematics I have.

Edited November 3, 2008 by MikeRL411

[jasperw4]

the 521 i picked up last week (http://www.debcar.com/Story-DatsunPickup.htm) had this happen today. i pulled the cluster and cleaned up the contacts and the gauges are now working but i don't think they are reading correctly. anyone have any ideas on where to source a new regulator? thanks!

[ggzilla]

Mike your conclusions are incorrect. For example, LB110 1200s have a voltage regulator for the instrument panel.

 

All Datsuns used instrument panel voltage regulator. It works fine in hundreds of millions of cars, so don't bag the idea just because your gauges are off.

 

Buy a new regulator from Nissan, if you confirmed that part is bad.

[jasperw4]

the pn for the 521 regulator is 25020-13200, local dealership shows it as backordered and unavailable.