How do you wire in a FIAMM horn and relay?

[Detman101]

The auto relay I used has 4-prongs. I got it from Radio Shack. Was that the wrong place to get one from?

12VDC/30A SPST Automotive Relay
? Coil Rating: 12VDC, 160mA, 400Ω
? Contacts and Ratings: SPST 30A at 12VDC
? Size: 2x1-3/16x1-1/8"


I took a fused line...

and ran it from the battery to the + side of the automotive relay(#85). I remember plugging another wire into the relay after that from the wiring harness. (#86)
Then I ran two wires to the horn from the relay, but the horn still doesn't work.(#87, #30) :?

I can hear the relay click but its like the power isnt' leaving the relay and going to the horn. It's properly grounded to the frame at the mounting bolt so I don't see why it won't work. Does that "Chassis Ground #86" have to be wired to the battery negative or the frame? Cause I've got one of the two wires that ran to the original horn hooked up to it....


Please help,
Dm of mD

EDIT: Technical info on the relay.

30A Automotive Relay
(275-0226) Specifications Faxback Doc. # 38002

Contacts: .................................................. .. SPST / N.O.

Rating: .................................................. .. 30A at 12 VDC

Coil Rating: ..................................... 12 VDC, 160 mA, 66 Ohms

Pick up Voltage: ............................................... 7.8 Volts

Drop out Voltage: .............................................. 1.2 Volts

Operating Time: ....................... 10 milliseconds at nominal voltage

Release Time: ......................... 10 milliseconds at nominal voltage

Operating Temperature Range: ............ - 30 to + 85 degrees C at 60% RH

Dimensions: .................................... 2 x 1 3/16 x 1 1/8 Inches

Terminal Connections:

Terminal # 85: ................................................ +12 VDC

Terminal # 86: ......................................... Chassis Ground

Terminal # 87 & # 30: ................................... SPST Contacts

Argh, I don't understand this.

Apparently from the relay's instructions...

#85 is where the battery plugs into it with the fused line.(fuse is good, checked)

#86 is where the ground wire goes. (is this one of the two wires from the wiring harness that went to the original horn?)

#87 & #30 are the SPST contacts (IE the switch)
I'm guessing that the two wires from the wiring harness go here on these connectors?? I tried switching the two wires from the wiring harness around on the relay and the horn still won't work.

But if this is teh case then what do I run to the horn from the relay?

God this is confusing...


Dm of mD

[Anonymous]

The relay should be wired as follows.

Terminal 85 is going to be connected to the wire from the harness that powered your old horns, it should energize only when the horn button is pressed.

Terminal 86 should be connected to chassis ground,, negitive on battery ect.

Terminal 30 should be connected to your wire that has the fuse link and constant power

Terminal 87 should be connected to the new horns

[my98xplorer]

I went to Discount and bought an air horn complete with a little bitty compressor and 2 air horns. I mounted to horns where the stock horns were and put the compressor where the tool kit was. It scares the crap out of people, i love it! :twisted: If someone can tell me how to post a pic i can post pics of what it looks like and how the relay is wired.

[Detman101]

EZ Rider....your explanation worked! I have horn!!!

WOOHOO!
Sadly, the brakes aren't working in the front.


Damnit, I didn't think the next issue would come so fast.
Back to work....*sigh*

:roll:
Dm of mD