My karcher window vac flashes green all the time but has no power

If you can hear the vac squeaking as you run across the window, you've just not applied enough liquid. Just go over the window again with the spray bottle and microfibre cloth and then vacuum the liquid away.

Do u need charge battery may be a fuse in plug or change power supply

Should be green...

Charge or replace your battery.

Carnac the Magnificent

Check the hoses for clogs due carpet fibers.

so notify karcher or place where bought for warranty work

batts fully topped up or dead

If you contact one of the Karcher Centers ( details are on Karcher.co.uk website) they may be able to help.
regards Gary

Have you tried to take it all apart just a small bit of rubbish will stop it from working.

Hi. I've just bought the karcher window vac wv50 & am having the same problem finding the serial No. I presume you want to register your product for the guarantee to be valid. I went online Karcher.co.uk & registered mine. You will note that when doing so it does not ask for a serial number but a model No. This is found on the side of box you got the item in (mine is just above the barcode) & it reads something like; 1.633-113.0. Hope you still have the box!

Take it apart and see what is stopping it (the motor) from turning .