Electrical fault?

[munfred]

When driving along I sometimes get the speedo needle dropping to 0 and staying there for a while. There is no pattern to this happening apart from it happening a couple of times on the same stretch of road on the way back from work.

Any ideas?

[mjb]

bumpy road?

You could try taking the instrument cluster out and re-seating the loom connectors... You could also do the same on the thing the Haynes manual says is feeding data to the speedo, but I dunno what or where that is

[steve_earwig]

It's behind the glovebox.

What version of 406 are we dealing with? Aha, V plate 406 HDI. As far as I know, not subject to the usual speedo control box cock-up.

[Welly]

[whisper mode] BSi? [/whisper mode]


*runs off*

[munfred]

Its happened a number of times on a straight flat road, so dont think its a bump or loose connection.

What is the BSI? what does it do? then I can go and smash it with a hammer.

[jameslxdt]

BSi - Body Systems Interface
also refferd to as Built-in Systems Interface
its basically an electronic unit that controls almost all the electrics in your car

[steve_earwig]

So keep that hammer in the box!

[munfred]

for some reason I already knew the answer to my own question.

Can it be a loose connection or damp getting onto connections?

[steve_earwig]

Of course, amongst other things. A good starting point though.

[Captain Jack]

As mjb said, take out the cluster and reseat it. It could be a dry joint on the PCB.

[teamster1975]

Dodgy soldering was my problem too; I ran all the joints on the sockets for the loom to the cluster which cured it.