Adding Horns to 2005 4Runner Sport Edition
- Thread starter Ryker
- Start date
[/URLThanks for all the help.
So I understand better for next time I'm messing with wiring and whatnot, can somebody explain why I ground the relay? I thought all I was changing was the 'trigger' for the horn?
Edit: I guess I didn't read [MENTION=105092]shOhio[/MENTION] 's explanation thoroughly the first time. I see now.
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Okay, so here we go:
Ill let y'all know how this works.
Might have to make some brackets, I'm not sure if the ones that came with the horn will work where I want to mount them, I don't thing they're long enough.
Side note: I'll probably have to test this a lot while doing it since they'll probably be be wrong the first few tries. My neighbors are going to LOVE me today :banana:
Fixed it for ya.
riceandpho
Elite Member
It's loud, but I can use a louder setup like train horns, still scare people when they swerve to my lane.
I'll mount longhorns on the hood and mount my new horns on the end of those :first:
kevinpt
Senior Member
The diagram isn't correct for this application. We can help, but you need to understand what's going on with the stock horn first.
The stock horns are pretty weak, right? That means they're not drawing much current. That means that size of the wire can be smaller. Think of it like a water pipe - bigger pipe, more water. Since the wire is small, it can run from the fuse box to the steering wheel to the horn under the hood. That's how the positive wire connects.
Your car's electrical system uses the car itself as a ground. The negative battery terminal is attached to the body with a thick cable. Accessories throughout the car can then connect directly to bare metal to ground. That's how the stock horn works. The nut and stud that connect the horn to the radiator support acts as the ground for the horn.
Therefore, there's only going to be one wire running to the horn. The wire running from the fuse box to the horn switch in the steering wheel is always energized when the car is on. So when you activate that switch by pushing on the wheel, you complete the circuit and the horn honks.
Using bigger horns makes things a little more complicated. Remember the water pipe above? We need to move a lot more water (energy) to run the big horns. More than we can safely run through the steering wheel. So that means that we'll need to go directly to the battery for power.
Every electrical accessory in the car runs through the fuse box. The point of a fuse is to safely melt a small, contained piece of metal before you'd melt a wire and light something on fire. Since we're going right to the battery, we need to add an inline fuse holder like this. Now we can run that wire over to the new, big horns. We can use another wire to connect the negative terminals to a bolt on a suitable spot of bright metal to ground it.
Now we have to somehow connect the horn button to these wires. That's when the relay comes in. The relay is basically a switch activated by a switch. The relay can be activated by a small amount of current, but can switch a much larger amount of current on and off. We'll use the stock horn connection we mentioned above to now trigger the relay instead. That power wire we ran from the battery attaches to the relay, as do the horns. We also need a ground. It comes together like this:
This is how you integrate a set of larger aftermarket horns with the stock horn switch.
so i wired up my horn like this and im getting nothing
LTDSC
New member
kevinpt
Senior Member
different purpose. same result
well after a lot of frustration i got it finnished. took like 6 hours but its done right. pulled it apart and checked each wire and it ended up being the ring terminals having poor connection
