Intermittent wiper not working

5MH58 · Post by **5MH58** » Sun Nov 15, 2020 9:20 pm

Hi all.

I’m new to the BMW world.

I have just purchased a 2008 Z4 and the intermittent wiper wipes once when selected but will not re-wipe after. Doesn’t matter where the sensitivity switch position is. Does anyone know of any known concerns with this issue?

If not does anyone have a wiring diagram and location of fuses, relays and components they could share with me please so I could check the circuit myself.

TIA

Stu.

colb · Post by **colb** » Mon Nov 16, 2020 11:50 am

Another thread running on here with same problem as you have here viewtopic.php?f=3&t=61659

ph001 · Post by **ph001** » Mon Nov 16, 2020 1:26 pm

You know they are automatic rain sensing right? If the windscreen is dry they will only wipe once. Try setting sensitivity to max and squirting windscreen with hosepipe, let us know what happens.

5MH58 · Post by **5MH58** » Mon Nov 16, 2020 2:08 pm

Yeah, tried the rain sensor with water before. No difference.

ph001 · Post by **ph001** » Mon Nov 16, 2020 5:41 pm

Can you take a picture of the rain sensor on the windscreen and upload to here?

5MH58 · Post by **5MH58** » Mon Nov 16, 2020 7:10 pm

Had to take it in the dark and used a lamp so the flash didn’t reflect.

5MH58 · Post by **5MH58** » Mon Nov 16, 2020 7:15 pm

colb wrote: ↑Mon Nov 16, 2020 11:50 am Another thread running on here with same problem as you have here viewtopic.php?f=3&t=61659

I saw this when I was searching for info but there was no conclusion and even someone has asked if it was sorted. I am swaying towards the BCM control unit (not sure if it’s called a BCM in BMW terms) but before I take mine off to send away for repair I would like to do some electrical checks via a wiring diagram.

ph001 · Post by **ph001** » Mon Nov 16, 2020 8:53 pm

Someone has been at that. You shouldn’t see any of those silicone blobs in the corners. Should be completely clean like this....

: 9F1126E5-B684-4E4A-AFD7-891BB0934B28.jpeg (84.24 KiB) Viewed 464 times

5MH58 · Post by **5MH58** » Mon Nov 16, 2020 9:45 pm

Ah ok. Good spot. Cheers for that. Would be so much easier if I had another Z4 to compare to. So now I’ve seen yours this will be my 1st step and hopefully it’s a matter of removing, cleaning and reattaching the housing as per bmw:windscreen spec. Now to find out the instructions of how it’s attached. Got a funny feeling that the housing will come with the screen. I work for a Vauxhall dealer so I will check the parts list tomorrow and see how we attach the housing (if it’s possible) or failing that I will ring out local windscreen company and ask his advice. Probably won’t be an update as the car is off tomorrow to have the wheels refurbished. Cheers again.

ph001 · Post by **ph001** » Mon Nov 16, 2020 11:48 pm

You’re welcome. The sensor has to be perfectly flat against the windscreen. I’m not sure exactly how it is bonded on but it defo won’t work properly if there is a gap like yours.

patriot66 · Post by **patriot66** » Tue Nov 17, 2020 4:46 pm

I recently replaced my rain sensor sticky pad as it was coming away from the glass and stopping the wipers working fully. I bought a replacement sticky pad on Ebay https://www.ebay.co.uk/itm/123394335324
The plastic housing covering the sensor is in two halves clipped together. Use a plastic panel tool to open it up. The rear view mirror also needs to be removed. Grab the arm of the rear view mirror and twist either way (iirc) about 1/3rd of a turn and it will uncouple from the metal key that is bonded to the screen.
Anything else you may need to know is in this step by step guide I found from Pelican Parts

https://www.pelicanparts.com/techarticl ... cement.htm

5MH58 · Post by **5MH58** » Tue Nov 17, 2020 7:39 pm

Thanks. That’s perfect. I removed the rain sensor today in my lunch hour. Wit it disconnected the intermittent wipe works so this in my eyes rules out the motor or power supply. The car has been dropped off for the wheels to be refurbished tonight so I will order a new sticky pad and reinstall it once I have the car back. Hopefully this is it

Z4-forum.com

Z4-forum.com