It will be the park switch in the motor, its the only thing it can be. Nothing else knows what position the wipers are in. I assume it must be a common fault on the early Delco motors as they were superceded in 1985 and later ones have to be fitted in place with an adaper harness.
What a nightmare, and what are the odds of the 2 wiper motors I have both doing the same thing!
Mind you, I hope not to be using the wipers much
If anyone wants to prove its the wiper motor at fault around a year ago Vauxhall were doing them for around £ 160 brand new!!!!!
I've had a look at the wiring section of haynes manual (It's a pass time I usually try to keep hidden). All the wipers mechanisms look the same (electrically at least). Some models have an extra relay but I will try to cover all types in my explanation of operation.
Here goes, deep breath.
All motor mechanisms have 5 wires, three are for the motor itself as follows:
Brown (ground)
White (motor fast speed)
Yellow (slow / normal speed)
Note there is no motor feedback itself, this is done by a sensing switch utilising the following wires:
Black/Violet (Permanent supply when ignition is on)
Blue or Green (Permanent supply fed back IF wiper mechanism is not in 'home' postion)
So when the motor is told to stop either by turning the wiper off or by the timing relay seizing its operation, the returning blue or green wire will be a 12V IF the wipers are not home. If you have a green wire, this means you have a relay fitted, if this relay has stopped its operation (give it a few seconds after using washer) the green wire going to it is connected to a blue wire via a normally closed relay contact. The blue wire of either type of circuit is then fed back to the wiper stalk. The stalk should now, if in the stopped position feed this supply to the yellow (slow) motor wire enabling it to carry on until the sensing switch senses the 'home' position therefore breaking the supply loop.
So the problem could lie in one of three areas, motor mechanism switch, relay contacts (if fitted) and finally wiper stalk - no great suprise. The way to go about fixing this in a methodical way without replacing all components is by measuring the voltage on the current path that should act to move the wipers down, that is (in order) Black/violet wire to green (if relay fitted) to blue wire to yellow wire. Where the voltage fails to materialise proves which switch / relay contact is at fault.
Personall speaking I think it will be a worn 'home' position sensing switch - maybe it wasn't the best design on earlier models?
Iain
If it doesnt happen all the time then the chances are it a loose connection or a relay mate!
both mine work fine?? not that int makes any difference cos im blind!!
Just to update you on this.
I changed the switch.. No luck
I changed the relay... No luck
Today I switch the motor and hey presto they park!
Originally Posted by novacabrio
Weird.... I changed another motor and it still didn't solve the prob, I must have 2 duff motors
nice, u got it sorted
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