Voltage Stabilizers (Stabiliser)

[sujitroy]

I went and put in some LEDs in the gauges of non running Stag no. 2. The tank is complete empty of fuel however, the fuel gauge indicated some fuel in the tank. I took the gauge out and calibrated it.
I then thought I'd check the voltage stabilizer against a calibrated fuel gauge. There's a TSB on how to do that using a 12 volt, 2.2 watt in series with the gauge. If the bulb flashes off and on, the stabilizer checks out to work. I then hooked up another working stabilizer to my fuel guage and bulb and noticed that the gauge's needle read higher than with the first stabilzer. Heres a couple of photos.
Stag no. 2 has a mechanical temp. gauge, but Stag no.1 still has the electrical temp. gauge and on long runs at 4000rpm (BW35) the gauge creaps up close to H, but never has crossed H and seems to be stable close to H. Anyway, I'm still experiementing and it seems like working bi-metal voltage stabilzers have too much variance and you are better off getting a new modern one with an IC in it.
Sujit

[StagJonno]

The stabiliser isn't really a precision device, though it does a fair job of producing a reasonably consistent average output for significant swings in battery voltage (~25%) and the gauges can only be considered as "indicators".

My stabiliser seems to work fine - if it starts playing up, I'll go the IC route. In the meantime - if it ain't broke, don't mess, though I appreciate that as you're doing a rebuild, you want it right..

[Phil S]

the only way to ensure the fuel and temp are correct would be solid state not bimetallic, but then what temperature is H on the gauge? the fuel gauge can at least be set by removing the sender to get a correct E and F setting

[Dieter H. Marschall]

There are reliable electronic stabilizers on the market. Some are even in the original housing ... Dieter.

[wilf]

Fitting one of those electronic stabilisers has finally given me a fuel gauge with an acceptable degree of accuracy. Two previous "mechanical" stabilisers did not.

Oil and water temps on my car are mechanical, I view the electric versions of those as very "vague indicators", and pretty useless for any meaningful diagnostics.

So my Stag paranoia is these days fuelled by better accuracy lol.

[Chix]

Finally found my voltage stabiliser, it had dropped down the back somewhere! But this wiring looks a mess. Looking at Haynes, the only thing supposed to be wired in is Green that heads off to fuse board and light green that goes to temp gauge and fuel gauge.

On mine, the temp guage is connected via that blue and red lead, check. The slate and black lead is spliced into the ignition wire (?!?!), the light green is as it should be, and the green I think is as it should be.

the fuel gauge green wire is loose and not connected to anything.

so my question is, what should be on which side of this voltage stabiliser?

all the light green on one side and the green on the other?

4EA4D950-7D4B-4931-B1FA-4DD3E76B344B.jpeg

[trunt]

The dark green is 12v ignition switched, the second wire goes off to somewhere else.. maybe the clock?

The two light greens are 10v stabilized, one for fuel gauge, one for temp gauge.

It needs to be grounded, normally its mounted on the speedo, you will find a small lug (for that bit on top of your picture) and a screw hole on your speedo where it mounts.

Terry

[StagJonno]

On the "Mk2" at least, the second dark green wire goes to the Tacho.

There shouldn't be any connection to the actual ignition circuit (ie White wire). The white wire is completely unfused, so any extension to the original circuit needs to be carefully thought out and need to ensure that there's no exposed conductor. Connecting to a dark green wire effectively by-passes the fuse in the Ign controlled circuits, increasing the risk of fire.

[Chix]

Ok thanks all, I’ve sorted it and hay presto, my fuel gauge is now working!! Rev counter is still jumping all over the frickin place though....

[StagJonno]

Is your's a MK1? I understand that these Tachos can have problems with operating correctly if you fit electronic ignition. Solutions are available to convert these Tachos - you might find some useful information if you search the Forum.

[Chix]

Is your's a MK1? I understand that these Tachos can have problems with operating correctly if you fit electronic ignition. Solutions are available to convert these Tachos - you might find some useful information if you search the Forum.

Yeah Mk1, but not electric ignition. My wiring is all over the place though, I'm sure the solution will emerge at some point!!

[StagJonno]

Good approach - you'll be an expert by the time you've finished.

I find the colour wiring diagram from http://www.classicdiagram.ukinanutsh...6/products.php very useful. It's robust A3 size on a magnetic backing. Normally lives on a steel whiteboard in the garage but easily moved to where I might need it.

[mallardstag]

I'm sure the solution will emerge at some point!!

If you are happy doing some soldering there is a kit available to convert the older (RVI) type to a newer and more reliable (RVC) type. You will also have to make some minor changes to the coil feed circuit to drive the newer type. In essence RVI (sometimes call inductive) tachos are wired in series with the coil primary (two wires to tacho) and RVC tachos are in parallel (only one wire to tacho). The kit also includes a cable which will allow you to calibrate the tacho against a sine wave produced by a phone app.

The older tacho is identifiable by the letters 'RVI' printed in small letters at the bottom of the gauge.

See eBay info here
Useful PDF article here.