13 replies to this topic

[Alex_grease_monkey]

Model: Mini Clubman (non estate)
Year: 1975
Description of problem :

Temp gauage faulty no reading atall, where should i start to look? where/what is the end of the gauge connected to?

and would this fit my car?

LINK

and if so how? straight onto the coil ?

just want a cheap one


Any non-standard parts that might be involved with the problem? no



Thanks

[rasputin22]

What sort of clocks do you have? Have you got the twin clocks behind the steering wheel or a centre clock n the middle of the dash.

Basically the circuit goes from a 10.5 Volt voltage regulator from behind the clocks to the temperature gauge then through the gauge to the sensor mounted on the front of the cylinder head on the right hand side, next to the thermostat housing.

The sensor varies its resistance due to temperature and controls the amount of current going through the gauge, hence it moves the needle.

If you have a multimeter put it on voltage setting then measure the voltage at the sensor end whilst the sensor is disconnected from the circuit, if no voltage then work up the circuit until you find a break/voltage.

My bets are on the voltage regulator being defective or a break in the line between gauge and sensor. The sensors are usually bullet proof and never known one go as yet. To test it put a multimeter on to resistance then measure the resistance between the connector and the block, whilst disconnected from the temperature circuit. Can't remember exactly the size of it but should be no more than 3000 Ohms.


Rev counter should work but you get for what you pay for so expect it to be pretty rubbish to be honest.

The voltage regulator also powers the fuel gauge sensor and possibly any other gauge with an electronic gauge as the voltage has to be stabilised.

[Alex_grease_monkey]

cheers for that,

i have the twin dial behind wheel

and i'll check the curcit and cables

not too fussed on the RPM gauage just like to have one for few occations i need one

[taffy1967]

You can also short the temp gauge spade terminal against the engine with a paper clip. Then with the ignition on your temp gauge should read hot. If it does then you need a new temp gauge sender. If it doesn't then it could be wiring related, or you need to replace the voltage regulator that's plugged into the rear of the Smiths Instruments gauges pod/cluster.

Edited by taffy1967, 23 December 2009 - 01:09 AM.

[dklawson]

As a footnote to Taffy's post I'd like to add a bit of clarification regarding the voltage stabilizer.

If shorting the temp sending unit wire to earth does not make the temperature gauge read "HOT"...
AND if the FUEL gauge is working properly...
focus your attention on:
the wiring from the stabilizer to the temp gauge,
the wiring from the gauge to the sending unit, and/or
the gauge itself.

If the FUEL gauge is working properly, this indicates that the stabilizer is OK and the problem is elsewhere.

[taffy1967]

If the FUEL gauge is working properly, this indicates that the stabilizer is OK and the problem is elsewhere.

That's not always the case because I once owned a Mini Mayfair fitted with early Nippon Seiki Instruments and like the Smiths Instruments, they still had a voltage regulator fitted to the rear.

The fuel gauge once failed on it (the temp gauge was still reading fine), but changing the voltage regulator fixed the problem. So I can only pass on hints from my own experiences.

Edited by taffy1967, 23 December 2009 - 08:39 PM.

[dklawson]

Thanks for that Taffy. I have only seen photos of the NS instruments and on those pictures the stabilizer was built into one of the two gauges. I was unaware that NS ever used an external stabilizer.

Regardless, if one stabilizer powers both gauges I'm curious to understand how one of your gauges worked and the other didn't... and why replacing the stabilizer would have addressed your car's problem.

[stormintrooper]

hello hello....my temp and fuel gauge seem to be both playing up barely reading anything with them....i have the Nippon S cluster behind the steering wheel...shorting the senders makes the gauges read full....where would i find my voltage stabiliser? and where would i get a replacement?


apolagies for hikacking

[steble]

just a thought u sure its not just the weather. me and my mates drove his mg zr all the way to newcastle on sunday thats 352 miles for us we live on the south cost. anyway the temp gauge never even started to read anything and its not because its broken.

[steve j]

I Chased a very similar fault to this a couple of weeks ago even bought a replacement guage which did not fix the problem. Check the windscreen wiper park switch this can cause problems with the guages they are on the same fuse.
If all else fails I do have a NS guage for sale but as I say check every thing else first then PM me if needed.

[stormintrooper]

wiper park switch is new

[dklawson]

Stormintrooper, check with Taffy to see if your NS gauges use an external stabilizer. He'll know where it is.

The pictures I was shown of NS gauges showed the stabilizer built into one of the two gauges, not a separate part that's replaceable. It was also an electromechanical unit like Smiths. I'm not sure what vintage that would make the NS gauges I've seen pictures of.

[taffy1967]

Well I know my local Rover (or Austin Rover at the time) dealer had to replace the voltage regulator on the late 1985 Mini Mayfair I once owned, because they sent me to another Rover dealer to fetch the component. I kid you not.

Anyway the Nippon Seiki gauges were introduced on the Mini in October 1985 and weren't a patch on the good old Smiths Instruments they replaced.

I believe the early Nippon gauges (of 1985-1987?) had the voltage regulator plugged into the rear of the clock pod cluster, as per the older Smiths types.

But the post 1987/88 Nippon gauges don't have a replaceable voltage regulator, because the regulating is done within the gauges themselves? So I guess that means they went electronic or whatever?

So it's usually bad news if the gauges fail on later Nippons, because it usually means they'll need replacing. Muck like my temperature gauge which hasn't moved since 2001.

[dklawson]

Thanks for that Taffy. I knew you would know what happened when.

The later type NS gauges I've seen pictures of had the internal stabilizer but as I mentioned earlier it was still an electromechanical device. It looked like the "guts" of a Smiths stabilizer built directly onto one of the NS gauges. Therefore, replacing the NS stabilizer would mean replacing one of the gauges. That said... a very enterprising person could probably take one of the later solid-state stabilizers and wire it in place of the NS guage's stabilizer. However, this would require nearly complete disassembly of the NS gauge cluster. Still... based on the pictures I was shown, it could be done.