Noticed when doing some work near the passenger side firewall, I found an unused 1 wire connector that is the same connector as the 2 horns mounted near the radiator. Did some digging in the wiring manual and it's labeled as "theft deterrent horn" This is what the whole thing looks like: There's nothing like it around where the connector is. If I press the alarm button on the fob, it sets the horns off on the front like most cars. So I have no idea what this third horn is for, was there some kind of factory alarm package? I did notice in the theft deterrent portion of the FSM, it says disconnecting and connecting the battery sounds the alarm, so I wonder if it was removed at one point? Because that would be annoying.
I think some Gen 2s had a glass breakage detection system. Maybe it's part of that. I think it can even still be purchased from Toyota and added if not originally on the car.
One of my cars without glass detection sensors It's an '07 I think has the horn mounted on the frame rail just above the crankshaft pulley on that side of the car I don't know what the hell it's for and don't really care this car I'm talking about is JBL stereo with rear tweeters on the back doors six disc changer and alarm but I don't think glass breakage at least when I look at that in the Toyota software plugged up to the car I can't turn it off or on or do anything with it it's grayed out so I'm not sure what that horn is really truly for It's the car makes the regular front horns beef also why would it have the spare kind of strange I haven't tried to make it beep it's just hanging there plugged up I don't think it ever works I'll check it tomorrow I drive the car every so often.
