Speedo Randomly Goes To Zero

[Dlcnffc]

HAPPY NEW YEAR! I have a focus Zetec 1.6 52 plate (2003). Recently i have had a problem that the speedo seems to loose all power and goes to zero. There is a slight loss of power to the engine (one time it started kangarooing). This rights itself after a few minutes and it's all fine again. It's happened 3 times in the last couple of weeks. I took it to the garage and they put it on the diagnostics checker thing for dash, abs and engine and all was fine, although they said that it registered a low voltage of 9.5 (this all sounds like I know what I'm talking about, but I don't - I got the garage to write it down for me!!!). Things to note is that all other instruments on the dashboard continued to work absolutely fine, including the odometer (I don't know if it continued to move, tbh, but it definitely didn't go blank or register ------- as seems to be the case in other posts about speedo problems) Can anyone suggest what it could be as I really can't afford to spend lots of money on this just to get no-where! Thank you!

[jeebowhite]

Welcome to the family,

It will be either the VSS, or the instrument cluster at fault. Unfortunately the Instrument Cluster is known to be inherently faulty....

[Stoney871]

The speedo dropping and loss of power are classic symptoms of a dud VSS.

If you look at the odometer it is highly likely that it isn't counting up, although in the early intermittent failure stage it does tend to work.

In later stages when the speedo drops for longer periods the odometer will definitely stop reading.

Before removing the sensor I recommend you check the connecting plug for corrosion/water ingress as it is exposed to all manner of road crud and wet conditions.

A replacement VSS and pin are fairly inexpensive on eBay, it's the removal of the old sensor that is usually the worst bit.

It can be removed either from above or below (depending on if you have ramps/axle stands/trolleyjacks etc.

The pin is a nuisance and usually snaps and the sensor needs twisting/pulling with mole grips ensuring that it comes out in one piece.

[Stoney871]

Another good tip is to soak the VSS and pin liberally with WD40 and leave to stand for 24 hours prior to removal.

Also grease the new pin and the upper seals on the new sensor before refitting.

[Dlcnffc]

Thank you all for your replies. Very helpful! Now at least I have a starting point. Thanks

[mjt]

On mine the identical fault turned out to be a chafed loom where it passes close to the gear linkage. Prior to this both the Vss and cluster were changed (under warranty) without fixing the problem.

[jamesm182]

My Dad used to have a 2003 Focus and his instrument cluster failed in a similar manner. It unfortunately seems to be a very common fault on the 2003 Focus specifically. It was even featured on watchdog a few years back (2008 I believe)