Screen wash mysteries

[Mitchen]

Interesting situation which I thought I would put out there. I've got a new genuine screen/headlamp wash control unit, that fits on to the front of the tank.. however since fitting it, when I push the stalk to activate the nozzles, the screen wash comes out continuously for like 15 seconds. I put the old unit back on and it works as normal.

Got a replacement from the dealer and the same thing

I know faulty batches, happen but it's extremely rare.

My HLWS has never worked and this was the first step of an overhaul. I'm wondering whether in the past someone has bodged something along the way and the new unit is bringing this to light. God knows what though.

Anyone come across this?

[BenHar]

That is the correct behaviour for the intensive wash.

One touch runs the fluid for a while and the wipers for a bit longer.

Ben