WHATS WRONG WITH MY KARCHER 620M?

I have a Karcher electric power washer Model 502MS. Nothing happenes when the switch is turned on. I opened the case and removed the cover to the switch and it works fine if I manually push the switch. When I reassemble the cover, it appears that the white plastic lever (that extends down from the on/off switch that pushes on the metal switch plate) does not go low enough to push on the switch plate. I made sure the cover plate is properly seated, the plastic lever is correctly inserted into the switch, it just seems I either need to extend the lever or raise the switch up. Could it be that I lost a small plate that the switch sits on when I opened it (although no online diagrams show anything under the switch)? What am I missing here?
Thx

Ed
September 2011

green light comes on but the motor fails to start. vc

vc
April 2011

Water pressure is too low

Pepper
February 2011

I have the same problem and will change switch, having problems disconnecting the detergent tank to get to the screws holding the switch. Any advice would be very much appreciated, thanks,
mick

Mick
November 2010

dear Stu Barr,
would you be able to send a picture of the switch with the wiring for me please? Seems my wires came lose and now i dont know where they go :s
Thanks
Anil

Anil Dhain
April 2010

my 620m switches on but the motor dont make a sound when i press the trigger only the power light is on could the motor be siezed?

calvin ho
August 2009

Stu,

Have had exactly the same problem with my Karcher. Took the thing apart (springs all round the kitchen), put it back together (very fiddly) seemed to be working alright until rebuilt it and now the thing still won't work.
Had resolved to buy the new part so glad that you cam confirm the source we both found seems the best and hope the replacement will solve my problem (cheaper than the £50 quoted by the local dealer just to look at it!)

Simon Pym
May 2009

Yeah as i had thought, fitted the new switch at the w/end and now got a perfect working 620M...no more brick method for me!

Hope this helps Guys!

Stu Barr
April 2009

I've had the same problem with my 620m. it eventually even had problems swiching on at all even using the brick on top solution.

The main problem was the on/off switch itself. I disassembled the karcher and removed the swich (if your doing this take a picture or two of the wiring before you pull the spade connectors off & make sure ur not pluged into the mains when you do this. the pics are always good reference when putting back together to ensure you reconnect correctly i make this common practice for any dismantling job i do).

once you have the swich out you can further disassemble this to access the actual internal workings of the switch by removing the black cover (careful not to break the lugs off, do one at a time in rotating order & for gods sake watchout for the springs when you take the cover off). My guess is (as was with mine)there has been previous arcing at the live or neu terminal which has melted the plastic latch mechanisim, hence will not stay latch on, latch off as it should.

You have a couple of options 1. Buy a new switch 20-30 quid or 2. repair it (go on give it a bash nothing to loose!)

If you are going to repair it, it may depend on how bad the damage is. Carefully remove / trim the melted disformed plastic only (it will have probs melted round the copper terminal )with a stanley and scrape the arced terminals to allow a better connection when operational. reassemble everything back together and the switch should now sound like the latching is clicking in & out of place (this may however not be fool proof. mine was badly damaged and seemed to latch on/off ok but once reconnected to the karcher it didn't repair the latch problem but at least gave me power again using the brick on top solution. I think the brick on top solution had been used for so long my swich had prob more damage than yours. however you could be in luck.

I was now happy my 620m would work again all beit i'd need a brick handy, but i had confirmed the problem was the on/off swich itself. once i'd confirmed that i decided to just go the 20 quid and i've just ordered a new switch to fully fix my 620m. like i said mine was badly damaged you might be lucky. if i were you id give it a go before ordering one.

if you are looking for a switch for it i found one for it on www.cleanstuff.co.uk they seemed the best price think it was 17 quid odd in vat. (make sure it's part 8)

I'll try and let you know how i got on after fitting the new one.

Hope this helps...let me know how you got on!

Stu

Stu Barr
April 2009