Morris Minor Owners Club

I am trying to fit a water temp gauge, when conected and the engine temp is 80c the gauge only moves a small amount, at 90c it does not move much more. When the sender cable is connected to earth the gauge shows hot.
At 20c the sender reads 1000 ohms, at 80c 70 ohms.
All the readings are the same, if a voltage stabiliser is connected or not.
The output voltage from the stabiliser is ramping from 6 to 12 volts.
I am not sure exactley how it works, or what it does, other than the name implies.
As I have exceed the annual budget, smiths gauge £3 sender £2 both from auto jumbles, I am looking for help what more checks I can make, other than "check book" repairs.
Thanks for all the interesting reading and information I get from the forum, Win

The VS is a bimetallic strip that vibrates and therefore opens and closes which allows then prevents voltage flow. By doing this it reduces the output from battery voltage to around 10volts which is what is required to run the temp gauge. There are 3 types of sender unit and it depends which gauge you have to which sender is required. The early smiths gauges which had numbers on them, I think, requires a black sender (a coloured colar around the sender identifies the type - either black, red, yellow, blue)
So, first check - have you got correct sender?
Second, make sure your input to the gauge is through the stabiliser.
Third - earth the sender wire which you have already done.
I guess either 1 or 2 may help.....

As above really - you should feed it through the stabiliser - which produces an 'average' voltage of ~10 - to the hot wire gauge. Does anyone know the resistance values of the different coloured sensors ?

Great answer PSL,Am fitting one at the moment along with a oil pressure gauge,And even i understood your explaination,A vibrating strip ! V clever ! All becomes clear now,and thanks for sensor info,Will save me no end of trouble !

It doesn't exactly 'vibrate' - but it does switch on and off - giving the average output to a hot wire instrument of 10 volts. If a bulb was fitted - it would flash !

However it would flash so rapidly that you probably wouldn't notice, I guess? Must try it one day when I have nothing better to do

*** "Vibration" refers to mechanical oscillations about an equilibrium point.

It is possible to make a stabiliser for less than £1 with the correct component from a well known supplier of electrical gizmos that begins with M and ends with N .It is called a Zennor diode and is very reliable. I looked for an alternative after a false gauge reading left me stranded in the middle of France, the outcome of which was €125 for a gallon of fuel. If you or anybody else are interested let me know.

pm sent, thanks to all who passed on info.

I think you can just buy a simple electronic voltage stabiliser from Maplins ? No need to be shy about suppliers - unless being negative about them! And I agreee - any movement back and forth is a 'vibration' - but we would normally take that to be a fast movement and I think the bimetallic make/break of the voltage stabiliser will not be too 'rapid' - however I haven't tried the light bulb myself.

http://mmoc.org.uk/viewtopic.php?f=11&t ... er#p311697

Try looking at this

There's a good guide to how to replace the voltage regulator with a solid state widget here: http://www.britishv8.org/Articles/MGB-V ... ilizer.htm using the Maplins part noted on the other thread (N38CA).

[frame][/frame] Voltage Stabiliser from Mini W/M