Horn upgrade for my Aygo

December 31, 2020

Hi all, I’m new to the Toyota forums, so be kind! My Aygo is my first Toyota since my last Corolla in 1992. It’s our third car, for nipping to the shops, pub etc. I have a Volvo XC60 and a Citroen Grand C4 Spacetourer and the Aygo is the smallest car/smallest engine I’ve ever owned. I absolutely love it - great to drive and work on, but the horn is a major issue for me. The first time I used it was when a bus pulled out on me, but it didn’t do any good. Playing back the Dashcam, the driver doesn’t even seem to hear the little squeak from my horn, so it has to be replaced.

I’ve bought a large train horn as a replacement and will post some pics and words to describe how it goes in case anyone ever wants to do the same. It’s quite easy if you have two things in your favour - enough space to mount the horn in the engine bay, and access to the existing horn to remove the wire connector. The Aygo appears to have both.

The first photo shows the size of the horn trumpet - it’s as long as the engine! I’ve tested it first including the compressor, relay and fuse holder. You don’t want to install it all and find something doesn’t work.

The second photo shows the existing horn with a single cable connected to it. This is located on the passenger side (RHD) behind the bumper lower grille and just in front of the radiator. I can see this is accessible by removing the plastic cover beneath the bumper, which appears to be attached by some 10mm bolts. I’ll jack the car up and pull the connector - I’ll make up a length of cable with a connector to attach to the relay. The horn can stay in place, so that I can reconnect it when I sell the car.

The third photo shows where I will attach the horn just to left of the engine bay and just forwards of the brake fluid reservoir. There are a few existing holes in the wheel arch, some with short threaded lengths. I’ll attach with a straightened 75mm angle bracket drilled and bent to suit the rear end of the horn.

The last photo shows where the compressor will go. This will be below the horn trumpet using a larger existing hole for the 12mm bolt and also take a piece of stainless steel strap to attach the lower end of the trumpet. I may also use this hole as the earth point for the compressor and relay.

I’ll post more when I do the next bit.

December 31, 2020

That should let them know that you’re around.🤣😂. Seriously though the horn on the Yaris is a meek little mouselike squeal and I wonder is there an upgrade that Is a straight replacement without doing any other work. Welcome to the forum Daniel and thanks for sharing, enjoy the Aygo.