Calling All Sufferers Of Dud Speedo's, I have the solution

Hi all,

Having read many times about failing speedo's I thought myself very luck not to have suffered that particular malady.... that was until yesterday. Glancing down at the speedo the needle was at zero but I was sure I was doing closer to 80 ! A couple of minutes later I was doing 80 again and it was OK for the rest of the return journey. Today it started intermittently and eventually failed altogether or so I thought. Visions of getting the sensor out of the gearbox were looming and I didn't much like the picture. Out of sheer frustration I thumped the dash with the palm of my hand and lo and behold it burst back into life. A little later, after hitting a pot hole it dropped again. Another thump and it came back on.

If you've got a dud speedo please try hitting the dash with the heel of your hand at the top right hand corner of the nacelle.

All joking aside, if I have what appears to be the same common fault as everyone else then the problem lies in the dash and maybe even the speedo instrument itself. The chances of a thump with your hand disturbing the wiring loom or even a connector is slim. And it certainly won't affect the sensor in the gearbox. The next job is to get the speedo out in my hands and look for loose or dry solder joints or maybe even something more obvious.

Please let me know if you're successful. It probably only affects those models with electronic speedo's. I don't think the traditional mechanical drive ones are affected.

cheers

noz

Hi Noz

I can confirm a sharp thwack works......for a while

The 2.5 I sold to Steve Fenton had the same, the PO to me had changed the speedo display unit but to no avail. The comp was reading the MPG etc ok so it must be a fault somewhere at the display end.

I wondered if there was another connection under the dash that was just as dodgy


Mark

thump the dash, iv been doing this to my 2.5 for about 6 months now?

I have a different offshoot of the same fault, after a few minutes it reads 55 all the time unless stationary.

As it does this even ifthe cab is cold or warm I can only guess its heat getting at the sender which is past its use by date.

If anyone has one spare I can use to test the theory before spending real money etc

damn forgot to put my name on that!

My "new" car, 2.0 turbo estate, has a non-working speedo. Thumping the dash with the heel of my hand produces a sore hand and nothing else. There is no readout from the computer, except fot "34" for miles left in the tank. Does this mean the sender unit is duff?

Derek

This is all very interesting, my red XM, with the intermittent fuel gauge now also has an intermittent speedo, which can apparantly be stopped or started by driving over a bump! First one to come up with the answer gets two free instrument panels!

Peter.N.