SPEEDO PROBLEMS
SPEEDO PROBLEMS
Author
Discussion

s3c chris

Original Poster:

310 posts

159 months

Wednesday 24th July 2013
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Hello again.
Considering I don't like computers I seem to be spending lots of time on this forum! The info you all give is first class, thankyou.
Whilst sorting out a few electrical gremlins I thought I'd have a go at the speedo problem.
It hasn't worked properly for a while and is now completely inoperative.
The previous owner had a new sensor fitted about 6 years ago so I assumed that would be ok. I managed to get a SH speedo from David Gerald (£80!) and fitted it today.
Firstly, it was made in 1998 and there are only two wires going to the connector, no earth screening being present. A phone call to David Gerald's suggested it "should be ok".
Duly fitted and a road test followed and no speedo, exactly as before!
I have checked power, earth and continuity of the circuit and all seems to be correct. Removed the sensor and checked the wires ( it was a "TVR" one) and that appears ok too, so I either have two U/S speedos, a U/S sensor or a combination of both! The wiring seems as it should be, so once again I am lost!
All comments appreciated, Chris.

chiefyo

279 posts

194 months

Thursday 25th July 2013
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I had a dancing speedo and the problem there was a poor earth to the case of the speedo. Totally seperate wire from connections to plug.

Barkychoc

7,848 posts

233 months

Thursday 25th July 2013
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Speedo notoriously crap, I got a new one made by speedycables and it was fab. Matched original, programmed with original mileage and lcd odo with trip aswell!

NiceCupOfTea

25,586 posts

280 months

Thursday 25th July 2013
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Barkychoc said:
Speedo notoriously crap, I got a new one made by speedycables and it was fab. Matched original, programmed with original mileage and lcd odo with trip aswell!
Barky, how much was that? My odo has stopped working. Wondering how hard it would be to take the back off it and ease the digit rounds (Stuck on 999!)

Spanish S2

341 posts

161 months

Thursday 25th July 2013
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NiceCupOfTea said:
Barky, how much was that? My odo has stopped working. Wondering how hard it would be to take the back off it and ease the digit rounds (Stuck on 999!)
My odometer started working again after travelling down a bumpy road.laugh

mohitos

1,313 posts

228 months

Thursday 25th July 2013
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Barkychoc said:
Speedo notoriously crap, I got a new one made by speedycables and it was fab. Matched original, programmed with original mileage and lcd odo with trip aswell!
Me too !

Got my first 3 points as a result of the old faulty speedo. It had stopped working the night before and I got caught at 37mph in a 30mph. Grrrr !

Anyway, another recommendation for speedycables - it looks standard but benefits form the LCD odo. I seem to recall it was about £150.

swimmer27

482 posts

211 months

Thursday 25th July 2013
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My speedo was replaced just before I purchased the s2 over 3 years ago, although it works its next to useless as it bounces around and will go from 70 to 120mph as soon as the cooling fans come on or the wipers are used, all earths are clean with most earth cables having been replaced.
With satnavs so cheap now I tend to use the satnav as my speedo now.

motorwurzel

71 posts

184 months

Thursday 25th July 2013
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Dear S3C Chris

I think there should be 3 wires to the speedo, 12V GND and pulses? You could do worse than attaching a GND wire to the case of the speedo and seeing if that helps?
Let me know how you get on?


s3c chris

Original Poster:

310 posts

159 months

Thursday 25th July 2013
quotequote all
Hi and thanks for the replies.
There are three wires on the original speedo plus a spade terminal for earth.
On the replacement, just two wires and an earth tag.
Tried both with no joy but the original is now stuck on 40mph!
Nothing from the replacement at all.
I'm reluctant to get a new sender at £140 as I know mine is not that old.
All wiring tests as it should and I've tried driving with a voltmeter connected to the pulse wire and earth (not sure if this is right or if I should see a signal on a cheapo multimeter) but nothing.
At least I know how easy it is to get the speedo out!
Would happily buy whatever I need to get it working again, just need to isolate the problem first.
Incidentally, if the sensor is not working will this affect the running, I know the pulse wire goes to the ECU.
Chris.

chiefyo

279 posts

194 months

Thursday 25th July 2013
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Chris I believe that I have a working sender that you could have a loan of if needed to help with your fault finding. I replaced this only to have problem remain and eventually traced to poor earth on casing. If you need it PM me.