Hey all,

I picked up the FIAMM El Grande horn kit from Amazon ( ), but am having some trouble with the install. It comes with the two horns, mounting brackets, and a relay. The relay has a 30 pin, 85, 86, and two 87 pins. Their diagram shows a fused cable coming straight from the battery, into pin 30, which I did. They show both 87 pins going to the horns, one to each, which I did. They also show the 85 pin being the OEM horn wire input, which I did. The problem is, they're not honking! Do I have to connect both OEM wires to the relay, one to 85 and one to 86? I thought the purpose of connecting the OEM wire was just to trigger the relay, so I didn't think it mattered if it was one or both. The horns themselves were grounded to the body of the XJ via their mounting brackets. Any ideas as to what my problem could be?

Thanks!

 

I'm not a Jeep expert, just an electronics expert. The horn relay is a simple device that allows a high current load (horns) to be activated by a low current switching circuit.

If you are replacing existing horns, the relay is not required for low current horns (5 amp) like the Fiamm El Grande. Your vehicle should already have a horn relay. Simply connect the existing wires to the new horns. If the new horns require 10 amps or more, a new (not additional) relay might be needed.

Now, let's talk about the relay. Relays contain one or more "contacts" that are activated by a "coil". The common horn relay has a double action set of contacts, normally open (NO) and normally closed (NC). These states are based on the relay's "shelf state", or the coil having no power. According to this link, , pins 85 and 86 are the relay coil, the "low current switching circuit". This 12 vdc coil requires a ground or negative on one pin and positive voltage on the other pin. The coil is not polarity sensitive. Either wire can be switched, which is governed by the vehicle wiring.

Pin 30 and 87, 87a are the relay contacts, the "high current load". Pin 30 is the common (C) contact and should be connected to positive voltage, preferably with an appropriately sized fuse. The positive voltage will go through the relay contacts to a load (horn). Use the normally open (NO) pin 87.

All of the relay pins can be verified or determined with an ohm meter. CAUTION: DO NOT USE AN OHM METER ON A LIVE CIRCUIT. The meter will be damaged or the internal fuse will be blown. Also, your hands and body can provide a resistance reading on the ohm meter. Make sure you do not touch both meter leads with your body because the resistance readings will be affected.

A relay coil should show a value of 5-50 ohms. The relay contacts should show either infinity or OL (open lead) from common (C) to normally open (NC), and 0-1 ohms from common (C) to normally closed (NC) contact.

 

Ground 86.

 

I guess I should have updated the thread awhile ago, but I got everything figured out and the horns work perfectly!