5 series estate; rear wiper and wash intermittent. Ideas?

First thing I'd look for would be a broken wire making intermittent contact. The earth would be easiest to check first by running some form of jump lead from the door to the body.

It will be the wiring in the loom of the tailgate. Common fault. Not too difficult to work on either. You will need some Torx tips for your screwdriver though. I'm a bit busy atm, but I'll see if I can email a circuit diagram tomorrow. Also check out

JB

Wiring looms (all 3) in the tailgate were replaced to fix problems with the lights. Since the washer is operated by water pressure (the spout thing elevates out of the tailgate but the pump is in the rear wing) I don't think this is it. I'm hoping it's the switch...

Thanks, I'm not convinced it's this. Mainly 'cos I had it replaced.

I would concur with this it seems to be a p[problem with the germa estates (done a few on the marks that preceded the E class) but if this has already been done then the water pressure may have to be the only solution remaining you sure it was routed correctly when it was refitted?

Given that it worked reliably for a week or so (last week) and hadn't worked before, I'd assume so.

I'm pretty convinced it's electrical before the tailgate. The switch is really the only common link but it seems too obvious!

You may have a split in the pressure pipe after the pump. Is the pump actually running? My pipe had a split and the water was running down the side of the tailgate.

JB

No, the pump isn't running.

I thought about that but... the lights work in the tailgate.

The wiper in the tailgate is handled through the tailgate wiring and the washer is a different loom. I'm pretty certain it's at the front of the car but without a ruddy pin-out for the wash/wipe control it's hard to work backwards. Or come to that any form of wiring diagram.

The pump is located inside the righthand side 'cubby' hole behind a panel in the load area. It may be worth checking that you've got volts present when the pump switch is activated.

JB

It's possible the lights have a different ground. And being plastic, don't pass it on.

Don't know if it's relevant to the 5 series, or to this problem, but on the E30 3 series touring the earth connecion of the rear wash switch goes all the way back from the dash to the wiper motor in the tailgate, where it is earthed by a sliding contact and metal plate inside the wiper gearbox.. The idea is that the washer only works when the blade is moving in one direction.