Intermittent rear wiper - 300TDi

Can anyone help?

The wiring colour codes doesnt seem, to tie up.
I have checked the switch in the dash and that switches power through checking the rear door plug, where it comes through the door frame, the Green/Orange converts to a Green/Lt Green in the body.

Checking power, the Green/Orange wire is live all the time when ignition is on, the Green/Brown wire doesnt have power irrespective of ignition/ wiper switch position, and Black is earth. I also have Brown/Yellow loop wire on the motor itself.

According to both Rave & Haynes the colours should be
White/Light Green
Brown/Light Green
Black
with a Red/Green motor loop wire.

Both manuals tell me there is a relay that should be behind the passengers footwell.... well, there are 5 relays, yellow, yellow, green, yellow and a brown. Nothing like the Blue, Yellow, Red, Red, Red and Black that are supposed to be there!

Hold everything!!!
Having followed a process of elimination, I have found that the middle one (green 5 pole) is the rear washer/wipe relay. Funnily enough it clicks when the rear wiper switch is depressed, and having identified it, removed it and replaced it, the rear wiper now seems to work, so it might have been a dirty contact, or I have just moved the wiring.

Lets hope it continues to work till after the MOT

you dont need a rear wiper for a mot

good.

sure it was an advisory last year

still - i prefer it to work

hmmm good thread, mine never worked since i got it, until one day out offroading, it miraculously started working. it was intermittent for a while and now nothing. So I think I'll check the relay now thanks to this thread :0)

Oh this could explain why mine dose not work right as we'll. oh well I will add it to the growing list of things to look at and fix.

lol mine is a bit hit and miss as well, sometimes i have to push the button 3 or 4 times before it will work.

had an issue on a 300 where rear wiper would only work when drivers door was shut, and opening the door to get out cancelled the rear wiper operation.
pain in the bum fault finding till we discovered it, seems its controlled thru the mfu to cancel operation incase driver gets out to open back door and gets caught in wiper.

dunno if it does it on all doors, we got it working so fault finding stopped.