I have a 1990 325is, the windscreen wipers work but only one speed, no intermittent, no fast and they do not self-park. I have removed and installed another K10 relay (2nd hand) with no difference, I have also directly connected power to pin 53 & 53b, the wipers worked but I did not notice any difference in speed.
Maybe related or not but also have a problem with the washers where only one of the three washer pumps work, the one on the o/s wing side of the tank. I have moved the pumps around to ensure that it is not a pump problem but the same result still only the one connection works.
Any suggestion what I should try next?
Wiper Electrical Issues
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
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- Joined: Mon Jan 10, 2005 11:00 pm
Although this forum is for all BMWs OTHER than E30s, you say it's a 1990 325i, so I presume this is an E30, and is in the wrong forum. I'll move it shortly.
The motor has one common carbon brush for both speeds, one carbon brush directly opposite the common one for normal speed, and a third brush for the high speed. The common brush is earthed by a brown wire, and black/yellow and black/white wires supply 12 volts+ to one of the other two brushes for normal and fast speeds.
If the motor doesn't run faster when powered directly to the 'fast' brush, then it suggests the motor is being mechanically overloaded. The self park and intermittent wipe depend on the crude switch in the motor's gearbox, which often fails to work because of hardened old grease, which could also be the cause of the motor being overloaded on fast speed, so opening up the gearbox, cleaning out and re greasing may be a good idea, but, on intermittent, the wipers should move about a third of a stroke, even if the gearbox switch is faulty.
The three pumps are for the normal screenwashers, the headlamp washers (second pump in large tank) and intensive wash (the pump in the smaller tank).
The headlamp washer pump is controlled by a switch built inside the RH headlamp wiper gearbox, which in turn is automatically controlled by the module clipped to the side of the washer tank. If the headlamp wipers don't work (often seized), then the washers will never work.
The intensive wash pump is controlled by a push button on the end of the wiper stalk. If the pump is good, and nothing happens when the button is pushed, then the column stalk is probably faulty, which could also be the cause of your wiper problems.
Disconnect the plug and socket for the stalk, which should be part of a stack clipped halfway down the steering column.
If you link the brown and brown/grey wires together, with the ignition on position 1, then the intensive washer pump should run (and the control module should start a wipe sequence).
If you link the brown and black/red the wipers should run on normal speed.
If you link the brown and black/purple the wipers should run on fast speed.
If you link the brown and black/blue the wipers should run on intermittent.
The motor has one common carbon brush for both speeds, one carbon brush directly opposite the common one for normal speed, and a third brush for the high speed. The common brush is earthed by a brown wire, and black/yellow and black/white wires supply 12 volts+ to one of the other two brushes for normal and fast speeds.
If the motor doesn't run faster when powered directly to the 'fast' brush, then it suggests the motor is being mechanically overloaded. The self park and intermittent wipe depend on the crude switch in the motor's gearbox, which often fails to work because of hardened old grease, which could also be the cause of the motor being overloaded on fast speed, so opening up the gearbox, cleaning out and re greasing may be a good idea, but, on intermittent, the wipers should move about a third of a stroke, even if the gearbox switch is faulty.
The three pumps are for the normal screenwashers, the headlamp washers (second pump in large tank) and intensive wash (the pump in the smaller tank).
The headlamp washer pump is controlled by a switch built inside the RH headlamp wiper gearbox, which in turn is automatically controlled by the module clipped to the side of the washer tank. If the headlamp wipers don't work (often seized), then the washers will never work.
The intensive wash pump is controlled by a push button on the end of the wiper stalk. If the pump is good, and nothing happens when the button is pushed, then the column stalk is probably faulty, which could also be the cause of your wiper problems.
Disconnect the plug and socket for the stalk, which should be part of a stack clipped halfway down the steering column.
If you link the brown and brown/grey wires together, with the ignition on position 1, then the intensive washer pump should run (and the control module should start a wipe sequence).
If you link the brown and black/red the wipers should run on normal speed.
If you link the brown and black/purple the wipers should run on fast speed.
If you link the brown and black/blue the wipers should run on intermittent.
Thanks for the replies, Brian yours was very informative, sorry about posting to the wrong forum, too much thinking about what to say and not enough about where to say it.
Took out the motor and cleaned it up the inside, contacts were greasy and the metal plate was badly pitted and rusty. Then took out the switch and cleaned up the earth connection and now seems to work OK although still not fast (maybe it’s as fast as they go).
I dissembled the R/H headlight wiper motor and not surprisingly it’s not working as its totally rusted.
I still have the washer problem with the intensive pump not working (with good pump) so it looks like either a wiring issue or the wiper motor unit fixed to the washer tank whose function I do not fully understand.
Any advice on fault finding the circuitry would be gratefully received especially a link to a wiring diagram showing the set up as my Bentley Manual only shows one pump so is not much help.
Took out the motor and cleaned it up the inside, contacts were greasy and the metal plate was badly pitted and rusty. Then took out the switch and cleaned up the earth connection and now seems to work OK although still not fast (maybe it’s as fast as they go).
I dissembled the R/H headlight wiper motor and not surprisingly it’s not working as its totally rusted.
I still have the washer problem with the intensive pump not working (with good pump) so it looks like either a wiring issue or the wiper motor unit fixed to the washer tank whose function I do not fully understand.
Any advice on fault finding the circuitry would be gratefully received especially a link to a wiring diagram showing the set up as my Bentley Manual only shows one pump so is not much help.
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Brianmoooore
- E30 Zone Team Member
- Posts: 49353
- Joined: Mon Jan 10, 2005 11:00 pm
Control unit on the washer tank is for the headlamp wipers only. It counts the number of times that the ordinary screen washers are used when the lights are on, and provides a start pulse to the headlamp wiper motors when the count reaches five or six.BrianHTCK wrote:
I still have the washer problem with the intensive pump not working (with good pump) so it looks like either a wiring issue or the wiper motor unit fixed to the washer tank whose function I do not fully understand.
Nothing whatsoever to do with the intensive wash pump.
There should be 12 volts on one side of the pump when the ignition is on, and the other side of the pump is simply earthed by the button on the end of the wiper stalk, via the brown/grey wire.
The control circuit for the intensive washer pump is part of the wiper module in the fusebox, which, when it receives the 'earth' signal from the button on the stalk, keeps the washer pump running for a few seconds, and activates the wipers as well.
Even if the wiper module is faulty, or even unplugged, the intensive washer pump should work while the button is pushed in.
The circuit diagram is in the Haynes E30/34 manual, 1948, which is available online as a free download.
Brian thanks for that, have downloaded Haynes and now understand circuit.
Quick check reveals no 12 V on connector. Also stripped back PVC tape on wires leading up to connector and discovered wires have been crimped together, did know that car had damage around the o/s front so potentially had to be rewired around there at that time.
Will focus on checking wiring next opportunity.
Quick check reveals no 12 V on connector. Also stripped back PVC tape on wires leading up to connector and discovered wires have been crimped together, did know that car had damage around the o/s front so potentially had to be rewired around there at that time.
Will focus on checking wiring next opportunity.