Dreaded rear harness problem?

[ScottyWM]

The rear wiper on my touring has started acting strange. It used to wipe once, pause, wipe once, pause, wipe once, etc... Now it has started wiping 5.75 times, pause, 5.75 times, pause, 5.75 times, etc...

The 5.75 is approximate by the way. Some times it seems to go exactly 6 wipes. It can take many cycles to get the wiper back to home position.

Is this a symptom of the bad wire harness? I thought then it just quit working. Everything else back hatch related works perfect. Is there a relay or something that might be bad?

[attack eagle]

I'd guess that you have a bad wire for the wiper park signal... should be red black... be aware there is another one in the same left harness which is red blue or red black for the hatch release.

I'm having all kinds of fun tonight playing around with mine... see my thread.

Also www.bmwe34.net has a great pdf with the color codes for each set of harnesses.

You may wind up fixing more than that once you get in there.

[ScottyWM]

Wow, just read your thread - that's a lot deeper than I want to get! IT hasn't rained her but once in the last 5 weeks or so (record draught), so as long as the problem doesn't get any worse I may just leave it alone. It just bugs me to have something that doesn't work as it should on the car! Keep us posted on your work, it sounds like it's info that would come in handy.

[ScottyWM]

Well, it's gotten worse. Now I see the rear defrost doesn't work. So I guess I'll be going into it to see what I can find. You say the wiper park wire is on the left (driver) side? That's the same side as the defroster, I may be in luck.

[attack eagle]

defrost adn 3rd brakelight are simple & sepereate two wire harnesses and the left adn right respectively. They go to the glass itself, not the hatch.

[Ferret]

This isnt a general module fault rather than a wiring harness fault is it?

Quick check before you go pulling your loom apart: lift the rear seats and see if you've got any water under there.

[ScottyWM]

I'll give it a check... but it hasn't rained but about twice all summer here. Any water would be from washing it, which I don't do much either:)

[Bo525i]

I just fixed both my rear harnesses so I know they´re good! Today my rear wiper started to do the same wierd cycle and I´ve been fiddling around and under the GM, thank god I´ve got another ;)

So checking your GM first is sound advice imo, could be age corrosion or what not!

[attack eagle]

be aware, the rear wipers have their own module, next to the relays for the hatch

that is behind the right side panel in the hatch area.
I sincerely doubt the rear wiper and washer runs thru the gm.

Check the park signal first.

[ScottyWM]

Yeah, Mine did turn out to be busted wire(s) in the harnesses. Re-did both sides, the defrost was busted on the driver's side - the wiper park busted on the passenger side. Once I got into it, there were other wires close to the failing point. Cut, splice, heat shrink, and everything works.

[Bo525i]

Well actually, there´s a S5 Wiper/washer switch connected to pins 4-5-6 on the yellow X255 in the GM :) But whether they have anything to do with the rear wiper I think not..

I think I better recheck my soldering on my red/black parksignal wire, I did get kinda stressed at a certain point when fixing it ;)