speedo woes

[Benjer182]

Hello all, the speedo on my 5 has stopped working, is this a common problem if so what am I looking for ? I know it's not cable but I'm not sure on the rest of the workings on it so so any help is appreciated
Thanks in advance

[Bigfoot]

Best thing is to clean the connector by the passenger turret by spraying WD40 in there. Has the speedo clock stopped working, might be worth trying another set if you can get hold of some. Just that the wires not melted if too close to the turbo.

[Matty]

I had a nightmare with mine trying to work out what was wrong.

An easy check to do to check the speedo is working is to pull the clocks out, leave the wires connected, switch the ignition on and bridge the two terminals on the plug. If you hold one end of the wire on one terminal and dab the other end of the wire on the other terminal you can simulate the pulsing of the sensor and check the clocks work. If the needle moves then it's either the wiring from the sensor, or the sensor itself.

If the needle doesn't move, then it could well be the coil inside the clocks. I ended up buying 3 sets of clocks trying to get a set that worked, and all had a broken connection on the coil inside the clock. It's a bit fiddly to get to, but I managed to swap the coil over from a working set of clocks to get mine working again. :agree:

It could also be a dodgy connection on the back of the clocks, where the circuit board ribbon cable connects into the clocks.

[J$£5GTT]

mines been playing up for years,LOL,fixed connector in the bay then it worked,then failed so changed clocks then it worked,now its failed again,cant be bothered to sort it at the moment so just been using sat nav for speedo.
:D:)

[J$£5GTT]

i would be keen to try and get another clock in the instrument console,something more reliable longterm? anyone have ideas for this and where to take speed readings from? pick ups?

[Mr Raider]

i would be keen to try and get another clock in the instrument console,something more reliable longterm? anyone have ideas for this and where to take speed readings from? pick ups?


OS8472 (Oli) had a pick up bracket/kit made so you can attach it to the driveshaft to work out speed. ;)

[J$£5GTT]

OS8472 (Oli) had a pick up bracket/kit made so you can attach it to the driveshaft to work out speed. ;)

:agree:

[Alex]

Check the connection on the suspension turret - clean it up and WD40 it. Plug it in and out several times. If still no joy clean up the connections at the back of the clocks with some fine wet and dry/WD40. If still no joy check the sensor in the gear box and make sure its attached and pushed in correctly.

After that its a case of replacement.

[Matt_S]

I'd try contact cleaner rathe than WD tbh.

[Benjer182]

Ok cheers guys I'll give cleaning it a go and checking the connections on the weekend

[Matt Cole]

I had a nightmare with mine trying to work out what was wrong.

An easy check to do to check the speedo is working is to pull the clocks out, leave the wires connected, switch the ignition on and bridge the two terminals on the plug. If you hold one end of the wire on one terminal and dab the other end of the wire on the other terminal you can simulate the pulsing of the sensor and check the clocks work. If the needle moves then it's either the wiring from the sensor, or the sensor itself.

If the needle doesn't move, then it could well be the coil inside the clocks. I ended up buying 3 sets of clocks trying to get a set that worked, and all had a broken connection on the coil inside the clock. It's a bit fiddly to get to, but I managed to swap the coil over from a working set of clocks to get mine working again. :agree:

It could also be a dodgy connection on the back of the clocks, where the circuit board ribbon cable connects into the clocks.

Matt, when you pulsed the speedo, did it move to 100% or just moved a little and then back to rest? Mine flicks but doesn't move all the way.

I can't get mine to work. I've tested the sensor half of the cable from the plug and get a reading of 02.4 ohms. I tested another sensir and that was the same. Can someone test a known working sensor for me using a multimeter?

[Ian S]

Measured from the black plug that's fitted to the grey wire that's fitted to the sensor,

I got about 5.5 Ohms. The terminals were corroded.

Three pins in the plug. Only two seemed connected.

[Matt Cole]

I'm might just cut the plugs off although they appear OK and seem to look OK.

My multimeter says 02.4 ohms? That was between the red and white wires? The meter cycles automatically from mega ohms.

I get full continuity between red and white wires.

[Ian S]

It's probably working OK then.

The Hall effect sensor generates a small voltage pulse from each passing gear tooth, that is applied, I presume, to the components in the instrument panel. So the problem may lay there if you have continuity from the instrument panel to the sensor. It should still be about 2.4 Ohms, plus any extra for the wire and connectors on the way.

I don't know anything about the circuit that deals with this signal. Maybe it amplifies the signal and applies it to the speedo drive electromagnet (if it has one), and the more frequent the pulses, the more drive there is to the speedo.