Wipers not parking properly by paulwatts1414



paulwatts1414
Hi, My wipers has just started to park anywhere apart from where they should, also when you put the stalk down for just one wipe they go about 10-12 before stopping,checked the nuts and all tight, do anyone know if its the wiper motor i need before i buy a new one, many thanks in advance,Paul

Posted 23 Aug 2012, 14:02 #1 

User avatar
Duncan
I'll have a look at the wiring diagrams when I get home, but it could be a broken wire between the BCU (Body Control Unit) and the motor, or a switch inside the motor. Could even be a power feed. Prompt me this evening if I've not posted what I've found.
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Posted 23 Aug 2012, 14:24 #2 


paulwatts1414
Thanks Duncan,

Posted 23 Aug 2012, 14:39 #3 

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kandyman
I seem to remember someone with this fault a few years ago, turned out to be the switch.
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Posted 23 Aug 2012, 18:07 #4 


paulwatts1414
Does that mean a new wiper motor will proberly cure it then

Posted 23 Aug 2012, 19:00 #5 

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Duncan
I've looked at the circuit diagrams, and there is a wire that goes from the wiper motor to the BCU. This wire tells the BCU that the wiper blades have reached the park position so the BCU can switch the power off.

So the likely problem is that the BCU thinks the blades are parked even when they are not.

To check, you need to check the output on this brown / light green wire using a meter at the wiper end. With the plug in and the wipers running, the voltage should change every time the wipers get to and leave the park position. My guess is the voltage should be low when they are not and go high when they are in park.

If the voltage is always low, then it could be a broken wire or bad connection between the wiper and the BCU. If it's always high it's more likely the switch inside the wiper motor, although the switch could also make it constantly low.

As a first step, check the connector for corrosion or broken wires. If you don't have a meter, see if you can borrow a wiper or get one cheap as it is the most likely point of failure, especially as Andy seems to have heard of this before.
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Posted 23 Aug 2012, 20:04 #6 


paulwatts1414
Thats brill thanks, will do as you suggest and let you know how i get on, again thanks, Paul

Posted 23 Aug 2012, 20:09 #7 


paulwatts1414
Hi Fixed the problem, it was the BCU, replaced it and everything is working great apart from the central locking, been told i need to buy a blank key and have it programed to the BCU at a cost of £130 per key from BMW, there must be a cheaper way, maybe get my orignal BCU fixed, anyone know who can do that please,

Posted 23 Sep 2012, 08:54 #8 

User avatar
Duncan
No, have a word with David (Monk) if he's close enough. You can program a used key to a new BCU so long as you have the barcode and you will have been told you need new ones because you don't have the barcodes. However David (and a few others) can help you even without.
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Posted 23 Sep 2012, 09:11 #9 


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