Rear washer intermittently activates without touching

My C3 has developed an issue where the rear washer will activate without any prompting from using the stalk, as a result of this the motor ends up running constantly and empties the washer bottle and consequently burns out the fuse. I initially thought this was an issue with faulty wiring but this isn't the case and think it may be to do with the relay switches or a low voltage ECU I would really appreciate any advice on this as I've taken it to the dealer who can't find the fault and charge me for no reason to run a diagnostic. Thanks in advance.

Sarge88uk wrote:My C3 has developed an issue where the rear washer will activate without any prompting from using the stalk, as a result of this the motor ends up running constantly and empties the washer bottle and consequently burns out the fuse. I initially thought this was an issue with faulty wiring but this isn't the case and think it may be to do with the relay switches or a low voltage ECU I would really appreciate any advice on this as I've taken it to the dealer who can't find the fault and charge me for no reason to run a diagnostic. Thanks in advance.

Its not a common problem but the COM2000 (stalks) can fail and give these sort of problems.

The test would be to use a lexia system like these to read the COM2000 signal for washer. Then you can work out if its worth changing the COM2000, just keep the fuse removed or look at the BSM (engine bay fuse box) for faults by swapping it out..


But, read up about the lexia system (here) before getting one.

I had the same problem it was the wire connector on the Com2000 which was not soldered properly.
edited typo

Not the easiest thing to fix, well done finding it. Thank you for the information.