There was a thread not too long ago (that has since disappeared) that got me looking into modding or replacing the wiper switch to give a mist feature. Several options were looked at including adapting other Toyota switch stalks (what I refer to as Plan A; Highlander switch in particular) or adding an external switch to cycle the wipers (Plan B.) Plan A would have been nice with a stock look and functionality but I couldn't locate a junk switch to play with. After looking at the wiring diagram, I did Plan B (wiper momentary switch) but it was a less than stock, cheesy solution.

[EDIT: Plan D utilizing a switch capacitor swap is now also done. See later on page 3 of this thread to modify the existing switch to increase the internittent swipe timing.]

So I came up with Plan C.
This still involves an external switch but it enables or disables the washer. This is an almost stock solution because you can pull back on the existing washer stalk switch to cycle the wipers with or without spraying the washer. Try this out in the stock condition before doing this mod if you are unsure of the usefulness of this mod for your own situation.

Bottom line:
Rocker switch ON + activate washer switch = stock wiper/wash action.
Rocker switch OFF + activate washer switch = mist+ feature.
I call this mist+ because the longer you hold the washer switch the more times the wipers will cycle. It takes getting used to, but you can cycle the wipers once with a short burst of the washer switch.

Here is the wiring diagram I referenced for my '04 T4R. Not sure if this applies to other years because Toyota has been known to change wire and stripe colours.

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184 035fww.pdf (25.5 KB, 697 views)

Start by disconnecting the battery NEGATIVE (-) terminal.
Then remove the steering wheel trim screws. 2 screws are behind the steering wheel (yellow arrow; rotate wheel as needed) and 1 is in the centre of the bottom trim (if you need a picture for this, then stop planning to do this mod and go back and visit the forums elsewhere.)

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Did you follow the earlier starting step: DISCONNECT THE BATTERY NEGATIVE (-) TERMINAL. (You are working near the air bag but not directly affecting it so avoid a possible mishap.)
Disconnect the Wiper/washer electrical connector (green box) and the wire harness holder (blue box; use pliers to pinch tabs in) to give you more room to work with the harness.
Split open the wire harness wrap with a utility knife.
Locate the Blue wire with Yellow stripe (comes from Pin #11 in the connector; blue arrows.)
Cut the wire and add crimp connectors (I used 2 different colours because that is what I had on hand.)
Add 2 lengths of 16ga. wire to reach the new switch location to the left of the steering column. Check the continuity of your connections back to Pin #11 just to be sure you cut the right wire.

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Here's another pic (less than stellar focus) with the 2 wires in place (blue arrows.) Route the wires out the final location with enough slack to fit the steering trim back on later. I was able to easily fish the wires into the trim panel opening. Add female tab crimp connectors and your rocker switch. Reattach the wiper/washer switch connector, connect the battery and test the switch functions.

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Tape everything up nice and neat, reattach the wire harness holder and reattach the trim covers.

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Final shot of where I located the rocker switch. This is a temporary switch hanging loose until I adapt a stock Toyota switch (probably the Taco fog switch) or find an adapter to fit the hole.
Mist away!

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The above mod can also be adapted to cycle the washer only (as someone requested in the original thread.) In this case, use only one wire from the "Blue with Yellow stripe" source wire (from the washer) to the new switch and then to a new ground. Use a push button momentary switch in this case. It's a little less than stock because you entirely lose the washer feature on the stalk switch but you retain the new mist+ feature.

I couldn't quite understand what you were trying to explain. Correct me if I'm wrong but, that switch is activated so you can pull the stalk and get a "mist only" action, correct?

Correct. The stock setup has a wiper action just like the mist feature when you pull the stalk, but you also get the washer spray. The new rocker switch lets you disable or enable the washer, but still get the wiping action, regardless, from the stalk switch.

"Bottom line:
Rocker switch ON + activate washer switch = stock wiper/wash action.
Rocker switch OFF + activate washer switch = mist+ feature."

Not to get too off topic, but whatever happened to that thread???

Can't you just flip the wiper stalk quickly down and then up to get one swipe of the wipers. Maybe I'm not understanding the issue.

Yes you can, and what most of us do. However, there is a certain ease that having a Mist feature on the stalk most of miss from owning other cars.

Well said, Mike07SE. Thanks.
There is also a certain satisfaction to modding. Finding and implementing a solution after the original poster to the missing thread (the OP must have deleted it) posed a question that got me thinking (in this case about a "mist" function.)

00328 and others,
There is no real "issue" other than the fact that we got cheated out of a wiper mist feature. Toyota could easily put this into the T4R, as a stock item for pennies, but chose not to while it chose to put this feature in lesser vehicles than our own. You can choose to do this or not. As I said in the original post:
"Try this out in the stock condition before doing this mod if you are unsure of the usefulness of this mod for your own situation."
Go out to your truck, turn it on and pull the stalk switch. Ignore the washer spray (pretend it didn't happen.) That's what got me thinking "how can I turn the washer off when I don't need it."

To each his own.

I was just thinking of this thread this morning; I was coming off the Bay Bridge into SF downtown and it was raining. I did the "poor man's mist wipe" - in other words flipped the stalk down and back up manually. Under normal circumstances this is really no big deal. However, while making a steady sweeping right turn down the offramp I was pulling my steering wheel RIGHT while trying to push my wiper stalk back LEFT at the same time with my right hand. A little weird. I think Toyota could have added a halfway stop when pulling the stock towards you for a dry mist wipe, then if you pull it even further towards you it could add the washer spray function. My old Acura had this. No big deal really on the t4r but it would be nice.

Good question. Not sure what happened to it. I remember it was quite a large thread too, which I was suprised it got so large

I did some searches and couldn't find it, so I'm assuming it got deleted. For what reason, who knows?