Is there any way to wire someone's brakes to their car horn?

I'm thinking about playing a really funny practical joke on a friend... :-)





What's the easiest way to go about doing this?

Is there any way to wire someone's brakes to their car horn?
would be helpful if you clued us in on what year make %26amp; model.





But to answer your question it can be done, Depends on what signal your brake is and what signal your lights are, amerage also plays a part.





the worst cast scenario you'd have to wire in a relay.But in order to answer your question, need year , make %26amp; model.





Don't listen to the other two posters below me, obviously they don't know what they are talking about.





I have seen first hand where the polarity differs on both brake switches and horns. Depending on what vehicle you have, could either have a negative pulse or a positive pulse.





You have ensure that the polarity of the horn coincides with that of the brake light switch.





If your brake light is a positive and your horn a negative, or vice versa a relay is required to change polarity.





Bosch 30 amp relay


85 %26amp; 86 are field coils


Whatever goes in 30 comes out 87, relays rest at 87a.





Hope this helps
Reply:yes, locate the switch that contols your break lights, tap into the side that is hot when the switch is activated run it to the hot side of the horn, when the switch is activated, so is the horn, this could also be a funny practical joke if you hooked it up to the blinkers so the horn honked in unision with the blinkers.
Reply:I agree with first poster - the 2 guys between us don't appreciate the finer points at all.





The horn relay is almost certainly activated by grounding the wire that goes to the steering column. The brake lights are just simply activated by a switch that turns them on. So the polarity is going to be wrong.





The horn relay coil on most cars is powered off the horn power supply. The brake light circuit won't be able to power the horn (too many amps), so you can't just hook the power supply of the horn relay to the brake light switch.





You'll need to put in a relay. You can use it to switch the polarity you have or you could wire the relay as a 2nd horn relay.
Reply:Actually that isn't very funny, it is vandalism. Imagine how thrilled you would be to find out your friend drove into a hospital zone and got ticketed for using his horn, or if he had to stop at a red light behind a police car. I would never forgive someone who vandalized the wiring in my car like that.





There are funny practical jokes that don't have to involve screwing things up, like stuffing a person's car with crumpled newspaper, which expands to fill the whole car, by the way, or buying one of those fake baseballs that stick to the window with fake cracks running out from it.
Reply:Don't even think about it. If you must play a sill prank may I suggest turning the radio wide open so they get blasted when they turn on the key.
Reply:Splice into a brake light bulb wire and tie it into the horn relay coil. You can't go direct to the horn because of the current it uses. It would blow the tail light fuse.





Sounds like a fun project to me.
Reply:jack his car wheels up about 1 inch / 25mm above the ground and sit it on axle stands.when he goes to move away it wont happen.his wheels will spin and its goin no where.



tanning