Speedometer wobble

[Johnie Boy]

Like Leighfos’s post in this forum on 25 May 09, the speedo on my wife’s Fusion 1.4 (53 plate) bounces, wobbles, and overreads, then settles down for a while, before starting off bouncing again.

I am fairly sure that the Fusion has an electronic speed sensor fitted to the transmission in place of an old-style speedometer cable (but there is no Haynes manual for the Fusion – they say to use the Fiesta Mk5 one instead).

The bouncing speedo problem may have started when I changed the clutch and had to disconnect all the cables etc from the transmission/gearbox area. I had difficulty disconnecting the speedo cable connector, so I removed the whole sensor (as if an old-style cable). The sensor had been bound in foil tape, which I unwound before removing the sensor. I rebound the sensor with the same tape on re-assembly.

I suspect the bouncing is because either the sensor is dirty or damaged, the cable connections are dirty or broken, or the tape binding is inadequate. I have briefly tried re-attaching the cable connections and re-binding the sensor, but got no improvement.

Before I try replacing the sensor itself, I would be grateful if anyone had any suggestions, or knew how to find what is really wrong?

Thanks

JohnieBoy

[chrbuff]

I have the same problem with my 1999 Ka. Hopefully nothing serious to fix as it is pretty annoying with a vibrating speedo needle!

[Shinysun]

Hi Johnie

Don't suppose you'd be willing to divulge the location of the sensor? I need to check mine on my MK6 fiesta but can't find it! The Haynes is too vague in description. Imagine I'm stood in front of the car facing it, is it on the left or right side?

My speedometer just randomly drops to zero, stays there for a while then pings back up again.

Hope you get your issue sorted soon!

Susan

[Johnie Boy]

Hi Susan

Yes the Haynes is vague, but (quoting another thread I saw) the sensor is fitted to the transmission in

place of the older speedometer cable drive pinion.

Indeed I spent some time convincing myself it was a sensor and not the pinion - but it does have an electrical connector and wires rather than a sheathed cable.

From memory, on our car it has a metal bracket sort of around it and is a pig to get to - sort of behind and under the transmission and close to the firewall.

If I seem a bit vague, it is some months since I changed the clutch, and I have tried to ignore the wife's complaints about the speedo wobbling - the rev counter works so watch that instead! However, I can't stand the heat much longer and must do something to resolve the problem!

Cheers

JohnieBoy

[Shinysun]

Hi Johnie

Thanks for that, at least now I have considerably more detail than before. Will get the bf to read your message and have a look!

I have become accustomed to using my rev counter and what gear I'm in to guess my speed!

Susan

Hi Susan

Yes the Haynes is vague, but (quoting another thread I saw) the sensor is fitted to the transmission in

place of the older speedometer cable drive pinion.

Indeed I spent some time convincing myself it was a sensor and not the pinion - but it does have an electrical connector and wires rather than a sheathed cable.

From memory, on our car it has a metal bracket sort of around it and is a pig to get to - sort of behind and under the transmission and close to the firewall.

If I seem a bit vague, it is some months since I changed the clutch, and I have tried to ignore the wife's complaints about the speedo wobbling - the rev counter works so watch that instead! However, I can't stand the heat much longer and must do something to resolve the problem!

Cheers

JohnieBoy