2006 C4 strange wiper problem.

[Paul-R]

My son-in-law was helping a neighbour with his C4. The wipers were misbehaving whereby when he unlocked the car with his remote they would start wiping back and forth and wouldn't stop until he put the key into ignition. Further to that if you switched the wipers on in the car they would only operate for about 4 or 5 sweeps. The wipers would stop anywhere on the screen and only sometimes where they should. Operating the washers worked but didn't then bring the wipers in.

This neighbour took the car somewhere and they said it needed a new wiper motor. A new one was too expensive so he got a S/H one and this is where my SIL comes in as he did the swap over. The motor came with linkage so he swapped it all over.

In case it's relevant, when he unscrewed the motor something was under such a strain that the motor sprung upwards and cracked the edge of the screen.

Anyway motor changed and the problem is the same. I suggested he bring it round and I'd see what codes are stored. I had to use my old Lexia as I couldn't find my Diagbox but it booted up OK. Three ECUs showed errors stored but nothing to do with the wiper. The error log was full but again, nothing to do with the wiper. I emptied the error log and then cleared the errors logged and when I did another global test no errors were showing. The wipers are still misbehaving.

He had already done a BSI reset but I did another one. Nothing changed (except for losing the configuration for the radio/time/date) so I'm at a loss.

Anybody got any ideas?

The best advice I could give was to sell the car with a known fault for what x=hundred pounds and buy another one. SIL tells me that the neighbour is thinking along the lines of a gallon of petrol and a box of matches!

[wheeler]

Get Lexia onto it & first check the live data coming from the Comms unit, make sure the commands on the screen match up to the stalk positions.
Next I'd be heading to the under bonnet fuse box & check for signs of water ingress in any of the plugs. The wiper relays are inside this too so could be a BSM issue.

[Paul-R]

Get Lexia onto it & first check the live data coming from the Comms unit, make sure the commands on the screen match up to the stalk positions.

I did check that all wiper switchgear positions were showing correctly on Lexia and they were.

Next I'd be heading to the under bonnet fuse box & check for signs of water ingress in any of the plugs. The wiper relays are inside this too so could be a BSM issue.

I suggested that it could be water ingress and he said he checked the fusebox and it didn't look as though water had been getting in. I also had a look under the cover and it did look fairly clean although I didn't take any fuses out.

I also still suspect the fusebox but the car had to go back yesterday so there's not a lot I can do but tell him to have a very close look again. Maybe take the box out even. Thanks.

[Paul-R]

Would I be right in thinking that as there was no ECU to read for the wipers that the fusebox is dumb and a replacement S/H one wouldn't need coding in? VF7**************[VIN obfuscated, can be read by forum staff] if needed.

[wheeler]

No wiper ECU & the BSM is not coded to the car either.