Happy New Year all

If we may call on th RRS tech gods again.
I know this has been covered in parts but we seem to be chasing our tails on this.

Front and rear washers do not work. Headlights do.

So far we have checked the pump by providing an earth to the cable going to the pump. However we assume that as the pump is providing for both front and back that the feed and earth to the pump are reversed for front and rear washing.
Fuse 38 and 43 are ok behind glove box which the fuse box guide says they are.
We can hear a clicking there but it doesn’t seem to be one of the 5 located there oddly enough?

So we have a feed to the pump but no earth. Does anyone know how the electrics work? Does the earth go through the bonnet switch? Where is the multi point relay that would switch the polarity?

A wiring diagram would be helpful if there is one around

Thank you in advance

Ian

What year of car are we dealing with?
Have you checked Fuse #11 which is for the washer pump on a RRS1

Thank you,
On the way fuse 11 has been checked also. But there is voltage at the pump so unless there is some magic wizardry going on in the way it’s routed it’s unlikely a fuse? Or would this be a wrong assumption? 2010 year.

Relay built into the fuse box.
Both pump wires go back to the relay.
And as you say reversed for front rear.

You should not short out the car loom

Did you get front working by powering the motor?

Last edited by Andy K on Sat Jan 06 2018 6:46pm. Edited 1 time in total

If there is a supply to the pump, then fuse 11 is fine, you are right in that the pump is bi directional, one way for washing the front and the other way for the rear. The wash pump relay R259 switches the live and earth to determine which way the pump operates, via two sets of contacts. This relay would be the next thing to check, plus check the earth to the relay and electric module D162 is good

Where this relay and module are located, I’m not sure but will have a look in the manual for you

You can't get to the relay to fault find or fix.

Thanks Andy, the motor runs in both directions if you power it directly and swap the around. It seems to be that there is power to it and no earth when the stalk button is pressed, so missing the earth return somewhere?
I’m not too sure what in the he system reverses this feed and provides the earth though?
Shorting out was for testing purposes to prove the feed and has since been removed.
Ian

Thanks GoDivaNige, as there is power there providing the earth does allow the front washers to work when pressing the stalk button.

You shouldn’t have 12v at the pump on either of the connections to it, if the front or rear wash on the stalk are not being operated. Both connections should be earthed with no operation. When you operate the front wash, 12v is then applied to one of the connections, if you operate the rear wash, 12v is then applied to the other connection.

That’s correct, 12v is present on the orange and black only when the button is pressed. Once the button is released the 12v is no longer present. It’s the earthing side that’s the issue as when the button is pressed there is no earth on the other cable (black and orange). Makes me think it’s the relay.
I think Andy is saying you can’t get to it though?

Yes, either faulty relay or a bad earth

I reckon it's a broken wire between pump and relay.

Is the relay accessible at all? Or even localised harness wires to it? It doesn’t make sense for a relay to be innaccesable?

Last edited by Itaylort on Sat Jan 06 2018 8:23pm. Edited 1 time in total

Hmmm, but if he’s getting 12v on each of the connections at the pump, depending on which wash is selected, the cables to the relay are good. What’s missing is the earth (at the relay)
With no wash selected, both connections at the pump should be grounded. If both are not grounded (which I suspect they may not be) then there is a bad earth or break in a cable to ground, from the relay.
It’s a simple check to disconnect the pump and check both feeds have continuity to earth with no wash selected.

I’ve got the wiring diagram on my iPad, just trying to figure out how to get a screen shot to post in my gallery

Itaylort, PM me your email address and i’ll send you the diagram

True


The car has about 50 inaccessible relays.