Intermittent wipers

[Andrew S]

Trying to help a friend sort their wipers out. Wipers work fine and at a good speed but on intermittent they stop and start. I swapped my delay relay over and it did the same but fine on my car. Interestingly enough, there is a single wire that attaches to the relay in addition to the block of wires and if I remove this wire the wipers keep going on intermittent.
Is it the relay?
It can't be mechanical if the main wipers work.
Any advice appreciated
Cheers
Andrew

[davidf]

'on intermittent they stop and start'

Late in the evening so feeling a bit facetious, but isn't that what they are supposed to do?

Sorry, I know you need a serious answer.

[trunt]

Yup better description would help.. what do you mean they keep going on intermittent? they just run I presume?

But if you installed your delay relay and its the same then its not that.

Its a complicated circuit see dasadrews drawings..

http://socforum.com/forum/showthread.php?31983-2-Speed-Wiper-Motor-with-delay-relay-circuitry-and-how-it-works

But I would initially weather the w/Lg wire actually gets grounded when you use the switch. maybe its a bad switch or connection.

[Andrew S]

Good point. What I meant was that only when you select intermittent when the wipers start moving, they go about 2/3's and stop and then there is a pause and they start again and stop anywhere on the screen but if I pull the wire off at the side of the relay loom block, they move continually.
So when I say stop start I mean they stop and start during the sweep and anywhere on the screen.
Cheers
Andrew

[zeus]

Hi Andrew,

Mine do exactly that too! so very interested in your conclusion.

Its like the park function does not work when on intermittant.

David

[tonyh]

Do the wipers park themselves when you switch them off? if not it's ether the tag on the end of the wiper rack broken or the park switch or slider.

Tony.

[Andrew S]

Hi Tony
I think they park OK, and both speeds work as they should, but its just intermittent mode where they stop and start as they go across the screen.

Cheer
Andrew

[trunt]

Good point. What I meant was that only when you select intermittent when the wipers start moving, they go about 2/3's and stop and then there is a pause and they start again and stop anywhere on the screen but if I pull the wire off at the side of the relay loom block, they move continually.
So when I say stop start I mean they stop and start during the sweep and anywhere on the screen.
Cheers
Andrew

OK so definitely parking, I'm guessing that the park wiring is routed through the relay on intermittent mode.

Without fully understanding the circuit yet I would check out the N/LG wire from the relay to the wiper motor, I think its that wire feeding the power to move the wipers via the park switch when it is operating in intermittent mode. it runs from the relay to the column plug and directly back to the wiper motor. as its working in normal mode my guess is a break between the relay and the column plug ( a bold statement, feel free to shoot that down guys
)


I think the Y/LG feeds power when the relay operates and thats OK as it starts moving every time the delay relay operates

[trunt]

OK investigated this as nothing better to do.. Thanks again to Dasadrew who's drawings I used extensively.

Wow that delay relay is a wierdo!

So at the relay:-

-Green wire is always 12v. When intermittent is selected at the stalk a ground is applied to one end of the relay coil via the W/LG wire.
-The non operated relay contact also supplies the 12v from green to the Y/LG wire and that is connected (via the stalk switch intermittent position) to the slow input of the wiper, so the wiper takes off.
-1/2 second later the relay operates, by now the motor is off the park position and 12v is supplied to the N/LG wire of the relay via the park switch - this is fed through the relay energised contacts to the Y/LG keeping the wipers running.

Here is the wierd bit.. (and the bit where I think yours goes wrong)

- The other end of the relay coil is connected to to Y/LG wire as well. Initially it is fed 12v from the green via the de-energised contacts. Once the relay operates the 12v from the park switch HOLDS IT ON This will keep the motor running until the park switch gets back to the park position.
-when its parked, the 12v will go away, stopping the motor, but the relay will stay energised for about 4 seconds.

-When the relay drops, it starts all over again. (12v on green wire sets the motor off..)

So I think what is happening is that the 12v from the park switch is not getting to the relay, (N/LG wire) this means the relay does not "hold" and also the wiper Motor gets no power when the relay operates.... The motor will stop after the relay operates (on my relay about 1/2 second) then after around 2 seconds when the relay drops - motor will start again for 1/2 second then stop again.

Note** If you pull the single wire off of the relay then the relay never operates so the 12v green wire permanently feeds the motor, it runs till you turn the intermittent off, (then parks using the NORMAL park wiring??)

So check the continuity of the N/LG wire, especially between the column plug and the relay board.

[Andrew S]

Thanks Terry
Interesting

Regards
Andrew