Problem with Corsa C imtemittent wiper

Constant live feed to the motor or the park switch inside the motor is faulty.

You can check for the voltage to the motor - one should be there for as long as the ignition is turned on and one just as the wiper switch is turned on. If the constant one is there, its likely the internal switch.

I had a similar problem once and it turned out to be the fuse.

Rob Graham

Thanks All. I'll check the relay and fuse at the weekend.

Please post back with your finding i am having a similar problem with my Combo van.

Tom

Bad earth through the switch? Most wipers are brought to a sudden stop by the switch not only removing power (which it temporarily resumed by the park mechanism until they get to the correct place) - the motor is then earthed through the switch / steering column. This has the effect of braking the motor when it starts to act like a generator with its own inertia,

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

================================================== My 95 Corsa's wipers stop as soon as I turn off the ignition, no parking.

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.

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.

No, inertia keeps them going a few mm...

FFS...do you even have a clue WTF you're talking about?

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.

If he were to do so, inside he would find a single-pole changeover switch. It would have one connection going to the motor, one going to either the wiper switch or the wiper relay, and the third connection going to..... earth!

Chris

:-)

Chris

Good luck "The-Sbray"

Let us know how you get along with the problem.

Are all the connections on the little gearbox end of the motor in good condition - this is where the self parking switch is located. Was it all new - or reconditioned?

Nope.