Toad A101CL 2nd Siren/Horn Wiring

Hi all,

I'm looking for help on how to wire a Horn to the alarm. The alarm system is a Toad A101CL which has the function for adding a 2nd Siren / Horn. This has to be programmed on the control module to which you want installed which I have configured to the Horn setting as I want to wire it to my car horn. I have checked to cable which is supposed to go to the horn and it have a constant 12v supply in normal operation conditions but when the siren is triggered, it fluctuates from 12v to 0v. Am I right in thinking this is a negative trigger. It also states that I need a relay for this. I already have a relay installed for the horn as I replaced my original horn for air horns but I'm not sure I can use this for the alarm too.
The current wiring for the horn is setup like this:


I would love to add the horn to the alarm as the horn is very loud and would be great along with the primary siren.
Any help with this would be much appreciated.

Thanks

Right now it appears your horn circuit is a positive triggered set up. You would need to add another relay from your alarm to control the horn being as it is a negative triggered system.

Great, thanks for the fast reply!

So I need to add another relay and wire it up like the picture below, but the green connection on the photo is the cable from my alarm module?

Good news. This wiring solution worked. Rearranged the current wiring layout to this for testing purposes and when the siren triggered, the horn triggered sequentially as it should. Now I've just got to order another relay and add it in addition to the normal switched horn relay.

Would diodes be required on each of the horn positives now as I would have two connections going into to the one horn positive from each relay or is this not necessary?