Hi, I put a new temp gauge in my car and as soon as I flick the ignition it jumps to H, what have I done wrong? Do i just need to switch the wires?

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Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

What sort / brand of gauge is it?

Happened to me once, a pack of Benson and Hedges smokes (the gold on the pack is conductive) found it's way behind the gauge. Shorted the sender wire to earth.......

its a new smiths. So i should be looking for an earth?

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Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

A new temperature gauge? Was it the gauge on its own or did it have a temperature sender included? I am supposing it is electric and not capillary as it comes on with the ignition...

As GT said, a dead short will also see it winging its way up to high as well, as will a mismatched temperature sender. Another possible cause is if it is an original smiths temperature gauge, they operate off of a 10 volt regulator and not the 12 volt battery voltage, this will also drive the reading very high.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

its a new temp gauge from minisport SA, they also supppllied the temp sender, although separately.

Am I correct in that I have wired it up as follows.
- Temp sender to back of gauge
- back of gauge to 12v

???

_________________
Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

Original smiths gauges came from a 10 volt regulator wired in and attached to the back of the speedometer. Like this one (photo was for the "name the mini part" thread )
Take a close look at the instructions to find out if the new ones remain calibrated for 10 volt use, but it also may be the sender is not the correct unit for the job or faulty.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Looking at the CAI website, I can't see a voltage reg being required...but this is a little ambiguous if the gauges are sold as new replacements of old units...

Here's the referring page, but have a look around to see if there's anything missed.

http://www.caigauge.com/page19.html

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

thanks for the link mick. As far as I can remember, my gauge only had two connectors. I will have to have another look.

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Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

So this is the gauge (just to be sure);

http://www.minisport.com.au/prod275.htm

and the sender;

http://www.minisport.com.au/prod133.htm

From my experience, these should work together, although it might always read a little on the warm side of N when wired without the voltage regulator.

Your description of how you have wired it up is correct.

OK, so, and again to be sure, as soon as your turn the key ON and the engine is not even running it goes to H?? It that is the case, then there either has to be a short in the sender wire to earth or the sender is faulty.

If you disconnect the wire from the sender and try it what does it do?

Do you have another sender you could try?

I think if the body of the guage is earthed (grounded) properly & the 12v is supplied via the regulator ("I" terminal), that should solve the problem.

My 20c worth.

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

Not to say they aren't out there, but I've not yet come across a smiths gauge that needed the body connected to earth to make the gauge itself work, fair enough for the light, it usually is necessary. Some of these gauges had plastic bodies. Connecting to the regulator might well be necessary.

You're right, the current path is from the supply through the bimetallic strip through to the sender. The grounded gauge case would only serve a purpose if the built in dash light needs an earthed case to operate.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Ok, so I looked at the problem.

It's not instant like I thought, but gradual. However, it reaches the H after less than 60seconds of running. So it seems to be functioning, but not properly. The motor isn't running hot.

Could it be the sender?

_________________
Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au

What happens if you disconnect the sender?

I'll check it in the morning.

_________________
Ryan Filippi
Minis In The Gong
[email protected]
www.minisinthegong.com.au