Fiat Coupe Club UK

Speedometer not working

Posted By: Anonymous

Speedometer not working - 02/06/2018 10:10

Hello All. After a winter lay up I noticed that my speedo isn't working and neither is the mileometer. This is on a 2000 turbo plus 6 speed. No other faults.

I suspect a bad sensor or poor connection or mice but I am unable to locate the sensor. I have removed the battery and tray and can see the reverse sensor but not the speedo. It must be around here somewhere but I can't find it. Can someone point me too it or perhaps have a photo of where it lives? I have looked in the manual under gearbox removal and it gets a mention but I can't understand the simple line drawing that goes with it.

Kind regards,
Rob
Posted By: Anonymous

Re: Speedometer not working - 03/06/2018 09:57

It's more down the back on the diff, easier to get from below. Near the end of the dipstick tube.
Posted By: Anonymous

Re: Speedometer not working - 03/06/2018 12:32

Thank you Graham, I managed to find it lurking where you said. Pretty rotten position, looks like an engine out job to undo it!!!

Thanks again, Rob.
Posted By: Anonymous

Re: Speedometer not working - 03/06/2018 14:56

I have the same car and the same problem! Do the sensors give up and, if so, any ideas where I could get a replacement? Thanks.
Posted By: dante giacosa

Re: Speedometer not working - 04/06/2018 07:25

you might be able to 'tap' the pulse in the wiring loom to check it is the sensor..

The pulse should be available as colours CB & (HM/)HR on pins 2 & 5 on Connector 149A (the big one, behind the battery)

in positions 2 & 5, on this connector, you should have Orange/White (CB) & (Grey/Brown/) becoming Grey/Red.
The colour change on pin 5, has Grey/Red on the 'engine' side of the wiring, and Grey/Brown on the dashboard side.

the negative reference for the speedo sensor should be an N (black) at position 14, on the same connector.

If you are clever; it might be possible to run some wiring from one of the first pair (pins 2 or 5), and the negative reference (pin 14), into the cabin, and feed a multimeter on AC volts, to see if you can see anything 'pulsing' during a slow roll across a carpark.

(I think i'd try this with the multimeter leaning against the windscreen from the outside, at SLOW speeds)

However, three factors may prevent a result-
*whether the speedo generates a decent pulse below 10mph
*the sample frequency of your multimeter
*and whether the relationship between the speedo and sender are compromised, and the speedo itself is dragging the pulse from the sender down.

But; I'd certainly try this first before attempting the sender swapout.

Posted By: Anonymous

Re: Speedometer not working - 06/06/2018 11:13

Thank you so much for the detailed advice
Posted By: Anonymous

Re: Speedometer not working - 11/06/2018 07:25

Many thanks Dante for a detailed explanation. I might try with the front of the car up on axle stands rather than drive along.

It might save a few grazed knuckles and my swear box.

Kind regards,
Rob
Posted By: Anonymous

Re: Speedometer not working - 11/06/2018 07:34

I have seen suitable sensors (I hope) on Ebay for about £25 e.g. https://www.ebay.co.uk/itm/FOR-FIAT-PANDA-PUNTO-UNO-BRAVA-BRAVO-BARCHETTA-COUPE-LANCIA-GEARBOX-SPEED-SENSOR/321276148349?hash=item4acd8cfa7d:g:m4EAAOxygPtSrjoK
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