Corolla E12 T-Sport - How to fix the alarm

[Shobobo]

Hi all,

First post here so I'm not sure if this is in the correct location or has been covered before but I've looked on the forums and couldn't find anything with a potential fix like this.

I'd recently bought my dream car - a Corolla T-Sport Compressor but at the time I didn't know about the alarm issue until a month into my ownership. I live on a road with terraced houses so the alarm going off WILL annoy the neighbours. Recently the horn wore itself out (probably due to the alarm) which gave much peace and quiet, but since replacing it the car is back to its usual antics... The missus has even suggested getting rid of the car.

Looking on the forums there have been mentions of the bonnet release sensor and the sensor near the interior light... I've had a look at the former and it has been disconnected in the past. I'm not too sure what I'm looking at around the interior light so maybe it's already been adjusted... can anyone help show me what needs to be done here?

Now, onto the main topic of the thread. I want to try and implement a couple of relays so I can decide whether I want the horn to work only whilst the car is in ignition/on or revert it back to standard at the flick of a switch. A bit of research and I think I've worked it out using a couple of 12V 30A relays. Having the horn only come on during ignition should solve the noise issue, where even if the alarm lights are on, there is no horn. If the car was being broken into, ideally the horn would come on if the thief tried to start the car.

I've attached the diagram for how I think it would work. As a complete novice in this and using only a few hours of googling as experience, is there anyone here that can confirm whether this would work/could be improved? I've spent a while thinking of how I could do it with just 1 relay but couldn't... so if someone with more experience could shed some insight onto this I'd be extremely grateful. Additionally, I was wondering where I could tap in for 12V ignition and 12V live feeds for the relays? Would pulling live straight out the Battery provide too high amperage?

I'll update this thread when I get around to doing it.

Thank you all for reading and providing any helpful insights.

[Obsidian Estate]

My suggestion was going to be the switch under the bonnet. If it's anything like the GT86 it'll be mounted on a flimsy metal bracket that's easy to bend when you're doing jobs, but as you say that has been disconnected it can't be that.