Fitting a temperature gauge.It read far too high.A solution!

[Handy]

Hi all,
I recently bought a Smiths reproduction temperature gauge from ESM. It's a superb bit of kit and it looks just right in my Minor,as you'd expect it to.
I fitted the sender to the head after removing the 3/4 inch bolt that sits just beneath the thermostat housing.
My car is still positive earth si I needed a switched negative supply which I took from the ignition switch.
I wired it up and fitted it.....Took the car for a run and the temperature reading was about 130 degrees Celsius.
To correct this, I fitted a 68 Ohm wirewound resistor in series with the gauge and it now reads possibly a touch low but it indicates 80 degrees.
This is a cheap and simple modification and I've got several of these resistors which I'll send out for free. I'll even solder wires on it and heatshrink it for you so that its safe!
Thanks for reading this,

Ian

[TerryG]

If you take the feed from the voltage regulator on the back of your speedo that powers the fuel gague then it reads accuratly without any extra kit or soldering.

[Pyoor_Kate]

....but check the output of your voltage regulator before you do because they can be a bit iffy (mine was reading at an average of 5-8volts, with exciting excersions to 15 and down to 1-2volts until I changed it

[Handy]

If you take the feed from the voltage regulator on the back of your speedo that powers the fuel gague then it reads accuratly without any extra kit or soldering.

I thought about this.The sender is positive and the stabiliser is positive too.I just assumed it wouldn't work?

[TerryG]

its working fine for me

[Alec]

Hello Handy,
These gauges are not polarity sensitive, so it will work with positive earth just fine.

Alec

[darren1camper]

i have just fitted a temp gauge and is reading 130 degrees. it is connect to the voltage stabiliser attached to the single green wire. if you could send one of your resistors that would be m ighty fine or an alternative. Also anyone know what oil pressure should be when warm?
regards
darren

[bmcecosse]

130 degrees is a bit low - should be ~ 160 degrees on a standard thermostat -assuming Fahrenheit of course! The gauge should be fed from the light green wire on the voltage stabiliser.
Oil pressure should be ~ 10 psi per 10 mph in top gear, up to 60 psi. So -at 50 mph you need at least 50 psi and in fact it should really be 60 psi at anything over 40 mph. This on a fully HOT engine.

[PSL184]

As this thread is 6 years old I think you will be lucky if the op sees this....! Anyway, if you wire up correctly there is no need for resistors of any type at all. You need to take the feed from the output side of the VS which will most probably have 2 wires on it. The input side, 1 wire, is 12 volts so the gauge will read high....

[darren1camper]

thank you for your help much appreciated. I connected the gauge to the single wire will swop tomorow. thanks once again.
regards
darren

[PSL184]

Post back if you're still having problems and we'll sort it for you....

[rayofleamington]

Also anyone know what oil pressure should be when warm?

If it stays above 20 on idle after a hard run on a hot day then it's ok.
If it struggles and the oil pressure light flickers on at idle on hot days, there are a handful of things you can do to extend engine life without having the engine out and fully rebuilt (make sure it's got fresh decent quality oil, check/replace rocker shaft, check / replace big end shells etc..).
Leaving it with the oil pressure light flickering is not going to help it live forever, but if you can ignore the rumbles they last a long time.

[darren1camper]

Hi there I have tried to connect to every wire and spare connection on the stabiliser, I either get no reading and no fuel gauge or fuel gauge works and temp reading far too high. I changed the stabiliser still no joy any ideas.
Regards
Darren

[PSL184]

Start off by telling us what you have connected to where, ie wire from sender, wire from stabiliser and which connections on the gauge you have them on.....

[bmcecosse]

Exactly what is the problem? Have you asked the supplier how to connect it/make it read correctly??