Wipers Staying On

[strobopug]

Hi Chaps, I have a good one for you...

Two weeks ago I drove home from a mates place in torrential rain. I noticed the rain sensor wasn't reacting as speedily as normal, but presumed it was just because of the dirty windscreen and thought no more of it. Just as I got home I knocked off the wipers, only for them to stay on. They stayed on even when I turned off the ignition and pulled the key. Pulling the control fuse didn't cure it either - the only way to stop them was to pull the main 25amp motor fuse.

I've replaced the battery, as I knew the old one was getting tired and presumed that might be the cause. I've carried out a couple of BSI resets, had the BSI out and re-soldered the joints under the relays in case the problem lay there, and now I've just replaced the wiper motor (as far as I could tell, the relay on the old motor was knackered - a hairline crack in the rubber surround that may have let water in, and what appeared on the multi-meter to be a short-circuit). Disconnecting the stalk makes no difference, nor does disconnecting the rain sensor. It has all the hallmarks of a stuck relay...

But these relays are tiny and tucked into the BSI unit where they can't be accessed, and I've not seen this problem affect these little relays before, so now I'm stumped...

My interior mirror drained it's auto-dimming fluid stuff the other week, and I wonder if there's a connection between this happening and maybe a problem with the rain sensor, but can't really imagine it. This is an area I know nothing about, but I had tried disconnecting the sensor when the problem first arose and it made no difference. Would a BSI reset AFTER disconnecting it make any difference? Could the sensor be sending a "wipe" signal to the BSI? If so, why does turning the ignition off not make any difference?

Any guesses chaps?

[lozz]

Hi and welcome to forum,

sorry youve had lack of replys of as yet:

Q: as your drivers floorwell ever got wet (water ingress)
if so iwouid check the connectors in the loom ..theres athread on the forum somewhere about this where it can play havoc with the bsi causing such Gremlins, might not be related to the same problem your having but it might be worth alook,

regards lozz,

[steve_earwig]

I presume the car is semi-mux (the change was in 2001 so it could be either) but it might be worth checking to save needlessly stripping the BSI - full-mux (com2000) cars have the relay in the engine fuse panel. It is possible to change the relays - this is a (French) pdf for changing the air con relay but it should give you an idea of what you're looking at http://www.coupe406.com/documents/Tutor ... im_BSI.pdf - the wiper relay is shown on the last page labelled "Relais essuie vitre avant".

[strobopug]

Cheers Chaps, yeah my car is semi-MUX. According to the build date it was built 1999, but not registered until 2001 - obviously not much demand for V6's around that time...

I've not come across any moisture in the footwells, or in the vicinity of the BSI or its earthing points. I've disconnected, cleaned and re-attached the earth contacts anyway, and this has made no difference. I had suspected that as it first happened on a very wet night it might've been moisture off my feet, but I'd literally stepped out of the house and into the car, so I was far from soaked.

The only relay I can't hear clicking at any point is the main on/off relay. With the ignition on I can hear the speed relay click if I change from I to II at the stalk, and I even hear the timer relay click off when I've pulled the stalk for the washers. The only one that's silent is the on/off relay...

Anyway, I might've got my hands on a used BSI that I can have a go at butchering and maybe cannibalising for parts. If I have any joy I'll pop back along here and give you all an update... IF I have any joy...