Speedo Jumped

[b0813y]

Hi,
I'm still new in here... and also located half-way around the world...

Is there anyone here have the same problem with me? My speedo needle sometimes jumped while accelerating
E.g. when in 100km/h, then accelerate to 150km/h, it sometimes move from 100 to 120 smoothly, then from 120 to 150 just jumped in a flash...
Is it the speed sensor, or I just need to clean the speedometer part...?

Thanks,
b0813y

[steve_earwig]

Greetings. Sounds a bit different from the ususal "doesn't work 'til you get to 70" problems, maybe a dodgy connection. What manifestation of 406 are you driving?

[b0813y]

It's a 2.0 1997 A/T.... it's quite random anyway, sometimes jumped from 120 to 140, sometimes directly from 100 to 150 (all in km/h)...
but, i notice that the needle movement above 120km/h is not as smooth as going from 0 to 120.

[teamster1975]

Dry solder joint on the back of the cluster or a fault on the control module which lives up behind the glovebox.
I had exactly the same symptoms, needle accurate to a certain point & then sticks and jumps to the correct speed. It slowly got worse and only read 40mph!
Re-running all the soldering cured mine but other folk here have had to change the control module; it's £40 from memory; loads of posts on it here.

[b0813y]

Hi, thanks teamster1975

Actually, I don't quite understand with "dry solder"...
Is it using a solder to clean-up all the component contact point on the speedo back PCB...?

[teamster1975]

Hi, thanks teamster1975

Actually, I don't quite understand with "dry solder"...
Is it using a solder to clean-up all the component contact point on the speedo back PCB...?

It's where the solder hasn't tinned properly onto the pad or component leg and made a good contact. It's a bit time consuming but you basically heat the existing solder to run it and dab a little new solder on the joint as well.

[b0813y]

okay, i got it now...
will try it on this weekend, i hope i'll have a whole day to open my speedo...

thanks alot...