Can you please advise how to add a "mercury switch" to a Prius' factory alarm, which I think is a door alarm only? A diagram drawing or photos will be really appreciated.
Do you connect one leg of the mercury switch to the relay 87a, the other leg to the Factory alarm door switch signal line (green one)? Relay legs 30, 85, 86 stay the same as in your diagram. Or can the mercury switch be connected directly to the ground & door switch signal line (green one)?
Did you see this diagram for the mercury switch, it goes between the door pin wire and ground? I have ordered one of the 507M tilt sensors, but I have an Omega AL-101 alarm box I can wire it to.
Mercury switch connected in parallel to plunger switch, that white line is factory one, in black sleeve need to find wire without ground to connect to. Let me know if more questions,
After 2nd cat stolen with Toyota tilt alarm installed it is obviouse it doesn't work. Instead it gets more costly. The thief knocks the driver side window, opens the hood and disables the alarm siren. Then it is no problem to jack the car up. They had 4 Prius' in the workshop with crashed side windows. So don't spend money on a tilt alarm unless you can hide the siren somewhere else. I will sell my Prius as a result of this.
Glass breakage and hood sensor. Unfortunately you would still have to deal with a broken window, even if they don't get to the CAT. In most cases, a good CAT shield would be enough of a deterrent.