Rear Wiper Intermittent Delay Timer Mod

[toy_toronto]

I am no expert in electronics whatsoever but the rear wiper delay is quite simple to achieve actually once you find the right module/kit.

Right now, if you turn the rear wiper switch ON and shut it OFF while the wiper blade is in the middle of the cycle, the motor still completes the cycle and returns the blade arm to "home" position. Wouldn't it be nice if there was a basic circuit that automatically turns the rear switch ON/OFF for you at specific interval?

Well I'm currently bench-testing a control module that does exactly that. It sends approximately half a second pulse or "momentary short" to the rear wiper switch connectors that activates the motor. The delay interval can be adjusted from 3 to 30 seconds for intermittent function via potentiometer which also happens to have it's own dedicated ON/OFF switch built-in. You still have the option to use the factory rear wiper switch as you would normally, but now you get a 2nd option where you use the module's potentiometer ON/OFF switch instead and set the wiper delay interval.


I'll post more details when I get everything installed and finalized this weekend -- but so far everything seems to be working perfectly without any issues.


-toy


P.S. picture below shows where the "short" happens when the rear wiper switch is turned ON:





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[toy_toronto]

I managed to do some more tests today, testing proof-of-concept to demonstrate such that the module can indeed send intermittent momentary pulse signals to the rear wiper motor and variable from 3 to 30 sec.

The actual wiper timer module I'm using is this: http://store.qkits.com/moreinfo.cfm/MXA041, and the best part is the price -- it only cost $8.95

The module shipped fully assembled and ready to hook up across the low speed circuit of our Yaris hatch rear wiper motor.


Here are some pics of the unit:





View of the connectors:




Bench Testing. When 12v is applied to the device and turned on, the COM and NO connections create an intermittent "short" every time the onboard relay coil is energized.

This momentary short could simply be applied to the rear wiper stalk switch that ultimately provides the desired delay interval.





Wiring it all up. I included as much detail as I could to the images below and hoping it explains in detail where I connected each of the wires to:





Here is where I mounted the delay timer module on the dash (mounted without a knob)





Knob that I bought seperately for a different/previous project:





Fully Mounted on Dash









...and there you have, a fully working intermittent rear wiper for the hatchback



-toy

[Lil Abner]

Very cool. I see you swapped your wiper stalk. Now someone just needs to figure out how to use that delay module with a swapped wiper switch. I bet CTScott knows what pin connectors to use!

[CTScott]

This is a great find. If I was to sell the one that I created, I would need to sell it for $20+ to cover my expenses, so $9 is a great deal. This could actually be used with the front wiper as well, to eliminate the need to swap stalks to gain adjustable intermittent for them as well (i.e. for $18 you could have adjustable intermittent front and rear).

[Lil Abner]

Originally Posted by CTScott

This is a great find. If I was to sell the one that I created, I would need to sell it for $20+ to cover my expenses, so $9 is a great deal. This could actually be used with the front wiper as well, to eliminate the need to swap stalks to gain adjustable intermittent for them as well (i.e. for $18 you could have adjustable intermittent front and rear).

Scott, in another post you said you added a pin to the wiper stalk to your delay module. Could you provide us with how you would implement this module into a newer wiper stalk (i.e. Prius one)? I'm assuming we add a pin, which goes into this module, then out to the wiper feed wire? Thanks!

[toy_toronto]

Originally Posted by Lil Abner

Very cool. I see you swapped your wiper stalk. Now someone just needs to figure out how to use that delay module with a swapped wiper switch. I bet CTScott knows what pin connectors to use!

I still have the OEM wiper stalk, but I do have an eBay order that used to belong to a 2004-07 RX330.

Originally Posted by CTScott

This could actually be used with the front wiper as well, to eliminate the need to swap stalks to gain adjustable intermittent for them as well (i.e. for $18 you could have adjustable intermittent front and rear).

This is definitely possible. I didn't really check which pins control the front wiper motor while I had everything apart --do you happen to know which they are?


-toy

[eTiMaGo]

could one also link a pair of these to the indicators, so that they'd keep blinking for a few seconds when the stalk is pressed lightly (as seen on BMWs)?

[CTScott]

Originally Posted by toy_toronto

I still have the OEM wiper stalk, but I do have an eBay order that used to belong to a 2004-07 RX330.




This is definitely possible. I didn't really check which pins control the front wiper motor while I had everything apart --do you happen to know which they are?


-toy

Prius Wiper Stalk.jpg

For the Prius, etc. stalk with the front intermittent and the multiple settings for the rear, there is a dead setting for the rear (LO), because the Yaris harness lacks the pin. That is pin 6 on the connector shown as C13 above (AKA D5 on the Yaris). Adding that pin will allow the LO setting for the rear wiper for the Prius stalk to be used as the intermittent rear setting with the module. I have the pin for that connector if you need one.

For the front wiper you would insert the module in line with the blue wire in pin 3 of the connector shown as C14 (AKA D6 on the Yaris) to make the fronts intermittent with the standard Yaris stalk.

[Lil Abner]

Thanks for the info Scott! Pin 6 for the rear intermit is an output, or input? I'll head outside and confirm that.

Last night I spent some time making a circuit with parts I had laying around. I was shocked I had everything. I'm using a 555, 100uF, 0.1uF, 10K-ohm, 500K-ohm variable, a couple diodes, and either a relay or output transistor. It's got a 0.7 second on pulse, and variable off pulse. Works great on the bench, now I'm planning on seeing if it works in the car. I think I have some pins (assuming their the same as the fog light pins). I'll try to post my results. I know people would love a DIY on this.

[toy_toronto]

Originally Posted by eTiMaGo

could one also link a pair of these to the indicators, so that they'd keep blinking for a few seconds when the stalk is pressed lightly (as seen on BMWs)?

eTiMaGo, I think its very doable. You'll need to use common negative of the circuit instead to keep the blinkers on longer.

Originally Posted by CTScott

For the front wiper you would insert the module in line with the blue wire in pin 3 of the connector shown as C14 (AKA D6 on the Yaris) to make the fronts intermittent with the standard Yaris stalk.

Thanks Scott.

For those with OEM stalk, buying a second module (or diy one like ctscott/lil abner is working on) is definitely the simplest/best solution.

I actually wonder how often would we really need to use both front and rear intermittent delays simultaneously. Perhaps instead of using two modules, one can probably get away with using just one comfortably. The OEM stalk already has Lo/Normal/Fast mode for front wipers, and simply add a tiny SPDT switch you get to choose either front or rear wiper motor to set the delay to (not simultaneously of course).

Originally Posted by Lil Abner

Last night I spent some time making a circuit with parts I had laying around. I was shocked I had everything. I'm using a 555, 100uF, 0.1uF, 10K-ohm, 500K-ohm variable, a couple diodes, and either a relay or output transistor. It's got a 0.7 second on pulse, and variable off pulse. Works great on the bench, now I'm planning on seeing if it works in the car. I think I have some pins (assuming their the same as the fog light pins). I'll try to post my results. I know people would love a DIY on this.

That's great Lil Abner --if it helps I scanned and attached the schematic of this module:




-toy

[Lil Abner]

Toy, thanks for the schematic. I see a couple things that are similar, but a lot that's different. My design has a lot fewer parts, so I hope it will be easier for someone to DIY. I have the circuit finalized, but now I'm trying to figure out a compact was to put it on a breadboard and solder it.

As for the delay, yeah, I honest doubt I'll really NEED a rear wiper delay. But since my stalk has a spot for it, I figure why not! And besides, it's just spare parts I have laying around, so it's not costing me anything.

However, I LOVE my delay on my front wipers! It was a worth-while investment. But your module is much cheaper than buying an OEM one. And I like your idea for a toggle switch. You could probably also add a second output relay to make your rear wiper go WITH your front wiper!

[toy_toronto]

^ and the possibilities are endless! :)


I'm not actually 100% sure yet if the stalk I have on order from a 2004-07 RX330 would work since everyone seems to have a Prius one.




I'm really hoping it works so I won't need to install a toggle switch or get another module *crossed fingers*



-toy

[Lil Abner]

Yeah, that one looks like it will work. I actually purchased a brand new one from the OEM part number, which fits a variety of cars.

Well, I got my circuit board all soldered-up. I tested it in the car, and it works nice. I just need to snap some pics, wire it into the car, then post up my results. Hopefully soon, cause I'm hungry!!

[MickZEL]

Originally Posted by toy_toronto

^ and the possibilities are endless! :)


I'm not actually 100% sure yet if the stalk I have on order from a 2004-07 RX330 would work since everyone seems to have a Prius one.




I'm really hoping it works so I won't need to install a toggle switch or get another module *crossed fingers*



-toy

This is an interesting feature I really miss her. In anticipation of the photo.
At Nissan, I had this feature.

[Lil Abner]

I don't want to hijack your thread, so I created a new one with the module I made:
http://www.yarisworld.com/forums/sho...209#post596209

[toy_toronto]

Originally Posted by CTScott

Attachment 43091
For the front wiper you would insert the module in line with the blue wire in pin 3 of the connector shown as C14 (AKA D6 on the Yaris) to make the fronts intermittent with the standard Yaris stalk.

Trying to implement a delay for the fronts, I inserted the module in line with pin 3 of D6 (blue) as you suggested and turned on the module --for each interval the motor receives a pulse but leaves the wiper in odd positions

I was looking at the EWD of the wiper switch assy. and noticed it might be possible while the switch is in the OFF position perhaps I can supply +12v to pin 1 (+S white) to make the wiper swipe then go back to "park" position... but I could be reading the diagram wrong, lol.


-toy

[Lil Abner]

Well, I know if the "ON" pulse isn't long enough, the motor will stick. Looking at your schematic, R4 and C2 control your "ON" pulse. The equation for time is:
T(on)=0.7*R*C
R4=10K ohms, C2=100uF=0.0001F
T(on)=0.7*10,000*0.0001
T(on)=0.7 sec

The only think I can think of is replacing R4 with a resistor around 14.7K or 15K. That would give about 1 second. Or just try that equation out and see.

Since you have the wires taken apart, you could also try this. Turn the wipers on low (not delay), and leave the wires disconnected. Quickly jump the blue wires together, and quickly disconnect. Try doing that slightly longer each time, until the wipers work properly. What you're trying to determine is the required ON pulse length needed by your module.

When I did my module, I only worried about the rear wiper, so I don't have any timing numbers for the front.

So you got the EWD for that switch? I'd hope it's simple, like you're saying, to just supply a ground and/or positive to one or all of those 3 little pins on the larger plug!

[CTScott]

Originally Posted by toy_toronto

Trying to implement a delay for the fronts, I inserted the module in line with pin 3 of D6 (blue) as you suggested and turned on the module --for each interval the motor receives a pulse but leaves the wiper in odd positions

I was looking at the EWD of the wiper switch assy. and noticed it might be possible while the switch is in the OFF position perhaps I can supply +12v to pin 1 (+S white) to make the wiper swipe then go back to "park" position... but I could be reading the diagram wrong, lol.


-toy

+S is the feedback from the cam switch, which tells the circuit in the stalk when it is OK to drop power and have the wiper land in the correct place. You can try connecting pin 2 to pin 3, which is what happens when you tap the stalk for mist mode.

This is what made life easier with my module, as I use a microcontroller, so I can program time intervals, rather than having to calculate RC time constants.

On another note, I got the Lexus EWDs last night and have bad news about your stalk. The RX330 with the "rain-sensing wipers" has an ECU that takes the sensor input and controls the wipers. It takes the place of the circuit that is built into our OEM stalk or the Prius, etc. ones with the intermittent fronts. This means that your stalk alone will not do the intermittent thing. You would either need the Auto Wiper ECU, or could use the Lexus stalk and use the auto position for your module. The "sensitivity" ring is just a potentiometer connected to pins 7 and 8, so you could use that in place of the pot on your board. It goes from 0 to 3.2K ohms.