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From: Les Ross on 8 Aug 2008 10:22
"Chris Whelan" <cawhelan(a)prejudicentlworld.com> wrote in message
news:oxVmk.127323$Lw1.62784(a)newsfe29.ams2...
> Conor wrote:
>
>> In article <BcLmk.89137$8w4.83879(a)newsfe30.ams2>, John says...
>>
>>> In normal operation if you switch off the ignition the wipers will tend
>>> to 'coast' to a stop. The wiper switch actually shorts the motor to
>>> earth
>>> to make it stop dead in the sector where the self park switch is
>>> aligned.
>>> Obviously a poor earth will allow the motor to coast on and then
>>> re-energise when the self park switch closes again
>>>
>> Actually it doesn't. It cuts the supply from the constant ignition
>> switched 12V. You're talking complete bollox.
>
> On pretty much anything decent made in the last 20 years, when the wipers
> are switched off the switched feed to the motor is removed, the constant
> feed powers the motor until just before the park position, the
> wipers "coast" the last few millimeters to the park position, and finally
> the motor is earthed to bring it to an immediate stop. A poor earth
> connection could indeed cause the wipers to fail to park.
>
> Conor, your Capri might not be wired like this, but your Mondeo is,
> without
> question.
>
> Chris
>
> --
> Remove prejudice to reply.
==================================================
My 95 Corsa's wipers stop as soon as I turn off the ignition, no parking.

--
Les Ross
Certified by a
Professional


From: John on 8 Aug 2008 10:29

"Les Ross" <me(a)home.com> wrote in message
news:WfGdnac62KAmywHVnZ2dnUVZ8vidnZ2d(a)posted.plusnet...
> "Chris Whelan" <cawhelan(a)prejudicentlworld.com> wrote in message
> news:oxVmk.127323$Lw1.62784(a)newsfe29.ams2...
>> Conor wrote:
>>
>>> In article <BcLmk.89137$8w4.83879(a)newsfe30.ams2>, John says...
>>>
>>>> In normal operation if you switch off the ignition the wipers will tend
>>>> to 'coast' to a stop. The wiper switch actually shorts the motor to
>>>> earth
>>>> to make it stop dead in the sector where the self park switch is
>>>> aligned.
>>>> Obviously a poor earth will allow the motor to coast on and then
>>>> re-energise when the self park switch closes again
>>>>
>>> Actually it doesn't. It cuts the supply from the constant ignition
>>> switched 12V. You're talking complete bollox.
>>
>> On pretty much anything decent made in the last 20 years, when the wipers
>> are switched off the switched feed to the motor is removed, the constant
>> feed powers the motor until just before the park position, the
>> wipers "coast" the last few millimeters to the park position, and finally
>> the motor is earthed to bring it to an immediate stop. A poor earth
>> connection could indeed cause the wipers to fail to park.
>>
>> Conor, your Capri might not be wired like this, but your Mondeo is,
>> without
>> question.
>>
>> Chris
>>
>> --
>> Remove prejudice to reply.
> ==================================================
> My 95 Corsa's wipers stop as soon as I turn off the ignition, no parking.
>
> --
> Les Ross
> Certified by a
> Professional
>

Of course they do - but they don't stop dead (as they would with a properly
wired) unless you perhaps have the heater fan and radio on - in which case
the inertia will be shunted through those items.


From: John on 8 Aug 2008 10:37

"Chris Whelan" <cawhelan(a)prejudicentlworld.com> wrote in message
news:oxVmk.127323$Lw1.62784(a)newsfe29.ams2...
> Conor wrote:
>
>> In article <BcLmk.89137$8w4.83879(a)newsfe30.ams2>, John says...
>>
>>> In normal operation if you switch off the ignition the wipers will tend
>>> to 'coast' to a stop. The wiper switch actually shorts the motor to
>>> earth
>>> to make it stop dead in the sector where the self park switch is
>>> aligned.
>>> Obviously a poor earth will allow the motor to coast on and then
>>> re-energise when the self park switch closes again
>>>
>> Actually it doesn't. It cuts the supply from the constant ignition
>> switched 12V. You're talking complete bollox.
>
> On pretty much anything decent made in the last 20 years, when the wipers
> are switched off the switched feed to the motor is removed, the constant
> feed powers the motor until just before the park position, the
> wipers "coast" the last few millimeters to the park position, and finally
> the motor is earthed to bring it to an immediate stop. A poor earth
> connection could indeed cause the wipers to fail to park.
>
> Conor, your Capri might not be wired like this, but your Mondeo is,
> without
> question.
>
> Chris
>
> --
> Remove prejudice to reply.

Thankls Chris for clearly explaining what happens.

Conor should know that a DC motor will act as a dynamo. Shorting the
'dynamo' creates a powerful braking force. If the braking force is not there
then the motor will coast a liittle allowing the wipers to re-energise from
the constant feed supply. This is controlled by a disc of contacts in the
wiper motor gear pinion.

The wiper switch either:

Provides power to start the wipers from the parked position - to enable them
to pick up the 'constant feed' - or it shorts out the motor.

I await Conor's next insulting response.


From: John on 8 Aug 2008 11:32

"John" <Who90nospam(a)ntlworld.com> wrote in message
news:2TYmk.189878$x66.147223(a)newsfe25.ams2...
>
> "Chris Whelan" <cawhelan(a)prejudicentlworld.com> wrote in message
> news:oxVmk.127323$Lw1.62784(a)newsfe29.ams2...
>> Conor wrote:
>>
>>> In article <BcLmk.89137$8w4.83879(a)newsfe30.ams2>, John says...
>>>
>>>> In normal operation if you switch off the ignition the wipers will tend
>>>> to 'coast' to a stop. The wiper switch actually shorts the motor to
>>>> earth
>>>> to make it stop dead in the sector where the self park switch is
>>>> aligned.
>>>> Obviously a poor earth will allow the motor to coast on and then
>>>> re-energise when the self park switch closes again
>>>>
>>> Actually it doesn't. It cuts the supply from the constant ignition
>>> switched 12V. You're talking complete bollox.
>>
>> On pretty much anything decent made in the last 20 years, when the wipers
>> are switched off the switched feed to the motor is removed, the constant
>> feed powers the motor until just before the park position, the
>> wipers "coast" the last few millimeters to the park position, and finally
>> the motor is earthed to bring it to an immediate stop. A poor earth
>> connection could indeed cause the wipers to fail to park.
>>
>> Conor, your Capri might not be wired like this, but your Mondeo is,
>> without
>> question.
>>
>> Chris
>>
>> --
>> Remove prejudice to reply.
>
> Thankls Chris for clearly explaining what happens.
>
> Conor should know that a DC motor will act as a dynamo. Shorting the
> 'dynamo' creates a powerful braking force. If the braking force is not
> there then the motor will coast a liittle allowing the wipers to
> re-energise from the constant feed supply. This is controlled by a disc of
> contacts in the wiper motor gear pinion.
>
> The wiper switch either:
>
> Provides power to start the wipers from the parked position - to enable
> them to pick up the 'constant feed' - or it shorts out the motor.
>
> I await Conor's next insulting response.
>

The earthing (shorting) of the motor will be done by the relay on most
modern cars. Look for an earth at the relay - as well as clean connections.

Another way of thinking about the switch is to think of it as a 'bridging
contact' across the 'at rest' position of the wipers. Once the wipers have
been powered by the switch or relay out of the parking position - the
circuit is maintained by the constant feed through the parking switch on the
gear pinion. The next time the wipers get to the parking position the motor
will either get its power for a few degrees of turn from the switch - or it
will hit earth and brake.
Hence the single wipe control is nothing more than a 'quick nudge' to move
the wipers into the sector where they get the feed from the constant supply.


From: Conor on 8 Aug 2008 15:31
In article <2TYmk.189878$x66.147223(a)newsfe25.ams2>, John says...


> I await Conor's next insulting response.
>
What is there I could possibly say that would be apt for such a level
of ignorance?

Perhaps you should take a wiper motor apart and then you'll see for
yourself.


--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams
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