Horn install and wire size

[tlartist]

I need to install two PIAA sport horns. Supposedly I can use the stock wiring but it looks pretty weak. How can I determine what load the stock wires support and whether what I plan to install will be a problem? Also, someone else said I could just increase the fuse size. How high can I go and which fuse would I replace. Any help is appreciated. Thanks.

[wjbertrand]

Use the stock wires only to switch a relay and then run 12GA wire from the battery (through a fuse) to the relay and then to the horn. Most aftermarket horns will overload the OEM wiring, switch contacts and fuses. In addition, using the wimpy OEM wiring will not let the horns develop their full volume.

Don't listen to mister "someone else" it is NOT wise to just increase the fuse size in the OEM harness. Those fuses are selected to protect the small wires that you have observed. If you put a larger fuse in there, you could end up frying some of those wires instead of blowing the fuse. Since these wires are bundled into the main harness with other circuits you stand to risk melting insulation from some of the other near by wires and pretty soon you're looking at a very expensive new main harness (best case) or a fire (worse case).

There are several posts here on how to connect in a relay.

[crazykz]

Does it say how many watts or amps the horns are? Chances are you may want to use a heavier gauge wire and use the regular horn wire to trip a relay but it depends on how much juice the new horns use. Also if you only use the horn for short honks you may be able to get away with a smaller gauge wire but I wouldn't recommend that.

Curt

[STingray]

This a nice wiring aid to answer questions like this: http://www.rallylights.com/other/wiring.htm

Google Stebel, and you get www.stebel.it/ I'm sure it can yield the draw of the horns. But based on the chart at rallylights, I used 14ga, which is still over kill (good for 20amps up to 18 ft) , but one can never be too 'safe'...

[tlartist]

thank you all for the help

Just ordered the horn wiring setup from easternbeaver

[tommyboy]

Jim is a good guy.