When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My silicone fix is no longer holding up. I have to press on the sensor now when it rains. What would be a good fix for this? The silicone seems to flex too much overtime, I don’t want to cause any damage with a permanent bond to the sensor if I need to have the glass relpaced again. I tried the tape solution but it is not strong enough and breaks free.
I wonder if a glass shop like a SafeLite store could help you. They attach rain sensors every day - maybe they have some tricks. I've never had a rain sensor fall off an aftermarket windshield that Safelite has installed.
I think I finally figured out my rain sensor... now I just wish it would rain so I could see if my sensor actually works.
I'd post pics but I'm unwilling to un-mount it now that I've gotten it mounted. Stealing tecman's pic:
This is the same setup I have. 4 hooks on that windshield bracket, the sensor, sensor housing and that strange clip.
1st - You have to add the gel tape to the sensor. It's Lexus part number 89944-42010, I got mine off ebay for about $10.00, but you can find it elsewhere. https://www.lexuspartsnow.com/parts/...944-42010.html Without the gel tape, the sensor doesn't touch the windshield. It's not really tape, just a strip of slightly sticky gel, so you can have multiple attempts at this, just try to keep it clean.
2nd - That plastic clip has to be almost fully inserted into the sensor housing *before* you put the housing on the hooks on the windshield. If you try to press the housing onto the windshield and then try to insert the clip, it's a no-go. To see what I'm talking about, take the housing off the windshield, hold it in your hands in good light, and put the clip in. With the clip almost all the way in except for about 1/4", you should see four openings where those hooks go. Pushing the clip in the last 1/4" or so grabs each one of the hooks (at least in theory). Again I should take a pic but now that's it's on there I don't want to take it back off.
3rd, and probably the most frustrating part - Actually getting the housing fully pressed against the windshield. Such a PIA. Assuming you have your gel tape on there, assuming you've become a clip positioning expert and have the clip inserted in that goldilocks zone, you have to get all four hooks / both sides of the sensor housing *fully seated* against the windshield. The problem is that the hooks are canted in such a way that it's very difficult to get both sides to fully seat, and the clip will grab just one side's hooks, leaving a very small gap on the other side. And it'll feel real great and solid too, even though one side isn't fully in contact. You know you didn't do it right if only one side of the gel tape is adhered against the windshield-- the gel should be completely flush with the windshield, no air on either side (it'll be almost invisible).
Again, for me, I couldn't just seat it on all four hooks at once by pushing straight up. The way I got it to fully mount was by getting one side's hooks completely seated/fully pressed against the windshield (the other only mostly) and then pulling the housing toward the other side while pushing up. Hard to describe, sort of like getting one side in and stretching it over the other.
Once you've got it fully against the glass, push that clip in the last ~1/4" of the way. Voila.
To summarize: 1) apply gel tape to sensor, 2) insert clip into sensor housing just right, 3) press housing onto hooks, getting one side fully seated and stretching the housing to grab the other side, 4) push clip all the way in.
Silly to think I went years without this. Nice when all the luxury features work on your luxury SUV.
Great!
I think I really take this feature for granted LOL. When it rained I just left it in Auto and pretty much forgot about it.
When I drove my Honda Odyssey or the wife's Camry I kept thinking that the autosensing would kick in anytime and forgot to turn on the wiper LOL.
Thanks Craigyyy. I will clean off my silicone and try your fix. I do have gel on my sensor that is shown in the pic. You had no gel at all on your sensor?
I had a GX470 and had the same problem after an aftermarket windshield was installed. We tried everything from a new pad to a new windshield. The rain sensor never worked until I insisted an OEM Lexus windshield be reinstalled.
Stealing tecman's pic:
Assuming you have your gel tape on there, assuming you've become a clip positioning expert and have the clip inserted in that goldilocks zone, you have to get all four hooks / both sides of the sensor housing *fully seated* against the windshield. The problem is that the hooks are canted in such a way that it's very difficult to get both sides to fully seat, and the clip will grab just one side's hooks, leaving a very small gap on the other side. And it'll feel real great and solid too, even though one side isn't fully in contact. You know you didn't do it right if only one side of the gel tape is adhered against the windshield-- the gel should be completely flush with the windshield, no air on either side (it'll be almost invisible). 
