jakenbake

Does anyone know if there is a way to unlink the headlight washer from the windshield washer? I want them to only work if I press the washer button next to the heated seat switch. It is really annoying when I have a little dust on the windshield and I wash it and the freaking headlight washers spray all over the front of an otherwise clean car. Plus, the headlight washers drain the tank so fast. When I went from BMW to Lexus, I was excited there was a separate button for the washers because I thought I could control them independently. :-/

Carver

#firstworldproblems Normal people concerned with this issue might simply block fluid going to the headlight washers. After all, we rarely face night time races through mud flinging conditions so dangerous as to require machinery to cleanse our headlights lest we die if they are non-functioning.

OTH, a mechanically inclined fellow such as yourself might spend a pleasant weekend engineering, accomplishing and photographing the process to share with your buds at CL.

Your choice.

jakenbake

NOTE*** This is for a 2006 RX400h...I can't guarantee that the wires colors and pin numbers are the same for every model of RX and each year of RX.

Well, I took Carver's advice and found my own solution. All you have to do is cut one wire. Now my windshield washers and headlight washers work independently.

There is a purple wire in the passenger side kick panel that tells the headlight washers when the window washers are on. If you cut the wire, they won't talk to each other anymore. AKA, the headlight washers only work when you press the headlight washer button. If you wash the windshield, the headlight washers don't wash.

In the passenger side kick panel there are four purple wires that ground when you wash the windshield. If you cut the wire coming from pin 10, the washer for the windshield won't communicate with the headlight washer anymore, thus letting your control the headlight washer and windshield washer independently from each other.

There are pictures below of the location of the harness that has the wire you need to cut. Since there are four purple wires in the connector, you must make sure to cut the correct one. If you cut the wrong one, the washer and auto wipers will no longer work.

The harness has two purple wires on the front side (closer to the passenger door) that are pins 6 and 8...and two purple wires on the back side (toward the engine compartment) that are pins 10 and 11. You want to cut the wire coming from pin 10 on the back side of the harness. (This is the purple wire most toward the center of the harness on the backside)

Here are some pictures to help you locate the harness. The most difficult part of this project is the fact that it is in a tight location. My big hands had a hard time fitting in the small space and I have a couple cuts and scratches from reaching up in there.

gundy

I thought the two washers were supposed to operate independently. At least mine do. I also found out from Lexus service that the headlight washers will only work (or supposed to) when the headlights are on.

jakenbake

Gundy...I would be surprised if yours don't spray with the windshield washer. Below is the part of the owners manual that explains how they are tied together.

pauljcl

As they state, only with the headlights 'on'. I checked my own 2009RX350, and, with the headlights 'off', the headlight sprayer is not triggered by the windshield washer. With the headlights 'on', both spray.

jakenbake

Correct pauljcl. The point of this mod is to make sure the washers never work at the same time while the headlights are on. Cutting that purple wire guarantees that the headlight washers do not operate with the windshield washers while the headlights are on. When I wrote this post I assumed that people understood that they only operate when the headlights are on. That was my mistake...I should be more clear in my writing.

I could not be happier with this mod. I can now wash my windshield (with the headlights on) without getting washer fluid all over the front of my car and wasting the washer fluid where it is not needed. If I want to wash the headlights (which I never do) I just press the headlight washer button instead.

gundy

Still strange that the headlight washers will only operate with the headlights on. I thought mine were broken until I found this out a couple of weeks ago. I guess I never needed to wash my headlights at night though I guess that's when you'd actually be using your headlights and thus need washing. Also seems silly to have both windshield and headlight washers operate together when only the former is activated. Instead of going through the wire cutting mod, you could just turn your lights off briefly then activate the windshield washer then turn the lights back on. Of course, that's not cool for customizers like jakenbake (I don't have the faith in myself to do all that stuff...).

jenright

Wondering if anyone tried to sever the connection to the headlight washers on a 2005 RX 330 as describe below?

My problem is a little different but driving me nuts and starting to cost a lot of washer fluid.

When lights on and the headlight washers come on, they on stay on, until the tank drains. The only way to stop it is to shut down the car and re-start. Sometimes even on re-start it keeps going.

This isn't happening every time I squirt but seems to be about every dozen washes.

I was going to simply stop the flow to the headlight washers but the pump is just going to keep going until it burns out.

Best would be workaround used by Jakenbake but want to see if anyone else has had similar problem and solution, otherwise I'll cut the wire and hope for the best.

Planner

I came on here looking for exactly the same solution and thought with the aid of your pictures I would be able to achieve it.

But I couldn't even find the group of wires I was looking for when I took the kick panel off! I'm sure it was just my lack of attention.

Essentially upside down looking into a rat's nest of wires, I decided just to take out the fuse in the engine compartment. Which obviously worked quite well.

If I ever need it I'll just put the fuse back in!