Replace original horn with Lexus LX600 genuine horn

Not sure what yours looks like, but if they're anything like the FIAMM horns I upgraded to, there should be some short black wires included with each horn. They have a push on terminal on one end, and a ring terminal on the other end. Use this wire to ground one of the two male terminals on the horn to the mounting bolt/bracket.

Then connect the other male terminal on the horn to the female oem connector from the car wiring harness.

So, in short, your horns weren't grounded properly.

SM-G781V ?

 

Not grounded properly

 

Does anyone know which side the 500hz vs 400hz goes to?

 

Doesn't really matter.

SM-G781V ?

 

I got my box from China yesterday (Lexus/Highlander horn kit) and got them in today....2021 Toyota Prius AWD. Just required removing the top black cover over the radiator area, didn't have to remove the front grill/bumper. Before I installed the new horns I plugged them in and tested them to see if they worked....NOTHING! What?? Then my engineer brain kicked in and said, "needs to get connected to the car, ground it dummy" And, yep, both are working and MUCH louder.

Some tips for y'all:

-Definitely will need a 12mm ratcheting wrench....very little room to get to the one bolt, especially on the left side.
-You just unplug the connector from the old speaker and then remove it with the bolt on the FRONT of the car frame....you can leave the other 2 or 3 alone.

The kit come comes with a new connector but didn't need to use it....it also has new 12mm bolts and zip ties...didn't need any of it.

 

I also just did mine the other day(I've had the kit for something like a year). And I also did the same thing you did by plugging it in and being confused why it didn't immediately work. Only when I took a close look at the plug and realized it was single pin did I begin to realize my issue. lol

(I made it worse by messing with the adjustment screw before installing. I didn't realize what it was for and tightened it down to the point it stopped the membrane from working. Once I loosened them, I got my nice, loud, two-tone horn. )

 

Just installed these on my 2019 Prius Prime. Very easy install and plug and play. All that is needed is a 12mm socket. I found that placing the 500mhz one on the passenger side and the 400mhz one on the driver side worked out best. Didn't need to use anything included in the box except the horns.

 

Can't believe the difference between these new horns and the wimpy original 'meep, meep' horn that comes with the '23-'24 Prius. This is definitely what you want to truly be heard when you honk the horn. I waited a year before doing the upgrade and almost got side-swiped by another driver with the original horn. The kit from Japan is inexpensive and complete and installs in less than 30 minutes.

 

You don't need any 'kit'. Any horn will work either alone or with the OEM.
I put a Ford Explorer horn from a salvage yard with mine

 

I chose a kit because there is only one wire on the Prius and the kit came with two horns (which I wanted) along with the splitter and the extra bolt for mounting the second horn. I realize I didn't 'need' a kit, for me it was convenient and cheaper than buying each piece separately. I really just ended up getting what I wanted (kind of like the Prius).

 

I have this upgrade for sale! Ran them for about a year and removed from car before I sold it. Like new includes 2 horns, harness, OEM box, etc...

 

Probably will get quicker sale if you list your price (with shipping), location (for local pick up) and a picture so people will get the idea of what this is.

 

The stock horn is a joke! 24 LE. Bought the horn kit on ebay for $65 which included shipping from Japan. The box included new high and low tone horns from the LX570, wiring harness, connectors and instructions in Japanese. Only tools required were a 12mm 1/4” socket, ratchet and flat blade screw driver. Used the flat blade screwdriver to remove the 6 pop up clips to remove the cover over the horn. Used the 12mm 1/4” socket and ratchet to remove the bolt holdng on the stock horn. Same tool to install the bolt on both of the new horns. Just pushed in the clip for the stock horn connector to disconnect it. Installed the new horn in the stock location first. Plugged in the new wiring harness to the stock wiring harness and then the two new horns. The entire install took about 15 minutes including using the kits 4 zip ties to attach the new harness to an existing harness and reinstalling the cover and 6 clips. The horn is plenty loud now!