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Electric Temp guage

PostPosted: Thu Apr 09, 2009 3:33 pm
by worzel
Hi All

This one of those jobs I've been putting off- better weather is re-energising me!

Having bust two of the combined oil pressure/temp guages in fairly rapid succession I decided to go the electric guage route for the temp. Because it matched the rest of the dials I went for an early Mini type guage.

It works- but the problem is that the needle takes ages to move off the bottom stop. Once it (eventually) reaches the mid-way point it stays there (it's pretty accurate too judging by comparisons I've made with the actual temp by using temp strips at various points.

It's wired thru a separate dedicated voltage stabiliser and I'm pretty sure the sender is of the correct type (but wouldn't swear to it).

Any ideas what the problem might be due to? One thing I have tried is to have a special steel adaptor made so that the sender screws into the head as far as possible (I thought the short reach of the sender might mean that it was too far out of the water flow. This improved matters but the slow initial reading is still present.

All connections are fine etc

Thanks in anticipation.

John

Re: Electric Temp guage

PostPosted: Thu Apr 09, 2009 9:47 pm
by neilsjuke
Gauges / sender can be 12v = no voltage stablizer or 5v / 10v with . And will not mix .I would bench test with a gauge meter (Smiths) .
Neil

Re: Electric Temp guage

PostPosted: Thu Apr 09, 2009 11:01 pm
by stugilmour
John, hoping I understand your set up correctly. Assuming the electric gauge you have retro-fitted is same/similar as Plus 2, which uses a screw in sensor and 10v nominal power supplied from the voltage stabilizer, which also supplies to fuel gauge. Plus 2 is of course a separate temp gauge rather than combo unit, but believe Smiths movement would be similar.

Have the dash completely out of my Plus 2 and in the process of testing all wiring and gauges. In any case, the damping in my temp gauge causes the gauge needle to move very slowly when power is first applied. Interestingly, this is the same for the Voltmeter (Battery Condition gauge) and fuel gauge as well; can't recall oil pressure reaction. Sounds like your temp gauge performance is the same as mine? This slow movement happens when testing by taking the sensor wire straight to ground, which results in the maximum reading on the gauge face. Seems to take about a minute or two to get to the max.

Open to correction on this, but thinking your revised setup is working correctly, particularly if final reading is correct.

Re: Electric Temp guage

PostPosted: Fri Apr 10, 2009 10:26 am
by worzel
Hi Again

Thanks for the input. One point I forgot to mention- might be significant- as the engine temp rises the needle doesn't move at first as I said but- if the glass on the guage is tapped is jerks away from the stop. On switching off the engine with the needle at the dead centre point is returns to the left ion a steady manner. Might this indicate a fault within the guage or is this normal?

Other cars I've had with similar guages move smoothly in both directions.

Regards

John

Re: Electric Temp guage

PostPosted: Fri Apr 10, 2009 4:36 pm
by steveww
On a slightly different tack; what do you use for an oil pressure gauge?

Re: Electric Temp guage

PostPosted: Fri Apr 10, 2009 5:31 pm
by paddy
worzel wrote:One point I forgot to mention- might be significant- as the engine temp rises the needle doesn't move at first as I said but- if the glass on the guage is tapped is jerks away from the stop. On switching off the engine with the needle at the dead centre point is returns to the left ion a steady manner. Might this indicate a fault within the guage or is this normal?


Obviously the movement is not perfect - I don't know whether or not there was any lubrication on the movement originally and perhaps it needs a miniscule drop of oil somewhere after 40 years. All of my gauges work more or less the same although when new they would have operated smoothly. Personally I've never bothered to do anything about it - the gauge won't be totally accurate but that's hardly a problem. If you do take the gauge apart and investigate further then let us know what you find.

Paddy

Re: Electric Temp guage

PostPosted: Sat Apr 11, 2009 12:12 pm
by worzel
Hi

Re the oil pressure guage the dash isn't std (I made it years ago) and has provision for another guage.

John