Custom Rear Wiper Delay Circuit on Swapped Stalk

[Lil Abner]

Ok, here's my final result. I used the information at this link:
http://www.kpsec.freeuk.com/555timer.htm#astable

I created an on cycle of 0.7 seconds, and an off cycle around 7 seconds. Only 3 wires were used to connect the module: Ignition (+), Ground (White/black on stalk), trigger (Blue on stalk). When the wiper switch engages the rear intermittent position, it feeds a ground to the circuit. The circuit takes that ground signal, and passes it through to the Blue wire for 0.7 seconds, every 7 seconds. Right now, I made the circuit non-adjustable. But it's easy to replace a resistor with a 500K potentiometer.

Bench Layout:
http://www.yarisworld.com/forums/picture.php?albumid=528&pictureid=4498

Soldered, before trimming the board:
http://www.yarisworld.com/forums/picture.php?albumid=528&pictureid=4499

In car, showing connections (thanks CTScott for pin-out):
http://www.yarisworld.com/forums/picture.php?albumid=528&pictureid=4500
http://www.yarisworld.com/forums/picture.php?albumid=528&pictureid=4501

And video, proof of concept:
http://www.youtube.com/watch?v=rxSQjWtRIx8

I think I calculated everything correctly, so there shouldn't be any issues in the future. All the parts can be found at Radio Shack. Price, I'm not sure. I buy in bulk, so I don't know what a Radio Shack total would run.

[birdman]

In one photo there is a red arrow pointing at something but it doesn't say what and the other picture has a red circle over a bunch of wires with no explanation. How is this helpful?

[BrickPig]

Only 3 wires were used to connect the module: Ignition (+), Ground (White/black on stalk), trigger (Blue on stalk).

In car, showing connections (thanks CTScott for pin-out):
http://www.yarisworld.com/forums/picture.php?albumid=528&pictureid=4500


Hi Lil Abner, I read your post with great interest. I have a Prius switch in my car but want to take advantage of the intermittent setting of the rear wiper switch.

In the image above, your red arrow points to a connection that you added. This new wire appears in your picture to be black. However in your verbal description you mention 3 wires: Ignition (+), Ground (White/black on stalk), and trigger (Blue on stalk).

Questions:
- Is the trigger wire the new wire?
- If not, what is the new wire (the one the red arrow is pointing to) for, and where does it connect?
- If the new wire is connected briefly to ground, will that cause the rear wiper to sweep the glass once?

Thanks in advance for your response. - BrickPig

[invader166]

I'm now attempting to build my own custom circuit.

Looking through the service manual, I managed to find this nice logic diagram:

http://i87.photobucket.com/albums/k137/invader166/Rear%20Wiper_zps2rocikp6.jpg

If I'm looking at this right, all I need to do is build a timer circuit that connects wire L (blue wire) to ground wire W-B (white wire with black stripe) for a short enough time (0.7 sec according to the OP) that allows the wiper motor to close the contactor in the wiper motor assembly via the eccentric cam lobe. Once that happens, the wiper should return to its original position by itself and remain there until the circuit is once again closed by the connection of the L and W-B wires.

Something else to take under consideration, the circuit itself must be able to withstand a transient current that is above the fuse rating. (15A)

I'll start working on this project in the next few days.