406 HDI wipers run for ten seconds

[djp30djp]

A fault developed wiyh the wipers on a 406 HDI 110 Executive Estate.
It comes & goes but is getting more frequent, when it started the fault would appear for a day or two then be OK for months, but now it,s the other way round.
When faulty the wipers run for 10 seconds when the switch is moved from any possition to any possition.
This gives about 9 wipes except in high speed when it's 12 wipes ( still 10 seconds), then the wipers stop weherever they are after the 10 seconds & the only way to park them is to turn the ignition off when they are at the bottom.
When OK all works properly including rain sensors, one wipe etc.
The rear wipe works OK all the time & the wash works fine but obviously the wipers run for the 10 seconds.
Any Ideas? I know its not the motor, seams like a wiper control unit fault but Being a HDI I presume all wiper functions are controled by the BSI?

[steve_earwig]

Not that I know what's going on but is this com2000?

[djp30djp]

No I don't think so, 'cause the switches are seperate.

[steve_earwig]

Then it looks like the relay is indeed inside the BSI (as opposed to under the bonnet on com2000 cars). On the last page of this PDF http://www.coupe406.com/documents/Tutor ... im_BSI.pdf it's labelled "Relais essuie vitre avant". Try changing the fuse first...

[djp30djp]

Great, thanks for that.
In the link it shows the BSI as being in the left footwell, but is it on the right in a rhd car?
Is it obvious orb is it disguised/hidden?

[highlander]

It's in the same panel as the cabin fusebox, right below the steering wheel. Open it up by releasing the steering wheel adjustment lock lever, and quarter-turning the big screws with a coin. The fusebox is the most noticeable thing there, but to the left of it, you should see a sort of grey box. Voila, that's yer BSI.

[djp30djp]

I was waiting until I could get a couple of days off when I didn't need the car so I could have a look see.
Then after a couple of hours driving in the heavy rain & moving the wiper switch every 10 seconds, to keep them working, suddenly they were back to working properly again.I mean rain sensing, one wipe & everything? Weird!
Only lasted about a week though & now it's back to 10 seconds running then stop anywhere. Really wierd!

[Doggy]

Try a BSI reset?

[steve_earwig]

A sound thrashing with a big stick?

Sounds more like an iffy connection than a proper failure.

[djp30djp]

I have tried the BSI reset - twice & checked all the fuses in both fuseboxes.
Everything else works correctly, even the side airbag light seems to be sorted now.
Tha bad connection idea sounds likely, but where?