4-horn relay questions

[70STOVEBOLT]

I recently got a set of 4 Cadillac 2-wire horns for my truck. Does anyone know if the stock horn relay will handle the amperage from the 4 horns, or do I need to add a relay or wire the horns in pairs and use two relays? I searched the web and cannot find a definitive answer.

[Steeveedee]

Look up that year Caddy at a parts store website and see if the relay numbers match.

[RustyPile]

Originally Posted by Steeveedee

Look up that year Caddy at a parts store website and see if the relay numbers match.

They probably won't match.. Wire the Caddy relay to your truck and hook up the horns to it..

[70STOVEBOLT]

Originally Posted by RustyPile

They probably won't match.. Wire the Caddy relay to your truck and hook up the horns to it..

I didn’t get the relay with the horns. I have read that the later horns (2-wire) don’t pull as many amps as the single wire but they are said to be not as loud also. I tested these with them temporarily connected together directly off the battery and they are plenty loud.

[truckster]

I've done it with the stock relay. The worst-case scenario is that you end up replacing the relay anyway. And the 4-horn setup sounds sweet.

[70STOVEBOLT]

Originally Posted by truckster

I've done it with the stock relay. The worst-case scenario is that you end up replacing the relay anyway. And the 4-horn setup sounds sweet.

I was planning on trying it, I have a spare relay but not sure if it’s good.

[70STOVEBOLT]

I hooked them up and mocked up the mount and it worked fine. I didn’t lay on it for more than a couple seconds, time will tell how the stock relay holds up.

[Steeveedee]

Originally Posted by 70STOVEBOLT

I hooked them up and mocked up the mount and it worked fine. I didn’t lay on it for more than a couple seconds, time will tell how the stock relay holds up.

Are you sure you're going to need more than two seconds worth of horn blast at a time?

[70STOVEBOLT]

Originally Posted by Steeveedee

Are you sure you're going to need more than two seconds worth of horn blast at a time?

Probably not

[70STOVEBOLT]

It’s plenty loud, at least on the garage

[truckster]

Originally Posted by 70STOVEBOLT

It’s plenty loud, at least on the garage

They're plenty loud out on the street as well. Every once in a while I'll end up behind someone at a railroad crossing and blow the horn, just for fun.

[Steeveedee]

Originally Posted by truckster

They're plenty loud out on the street as well. Every once in a while I'll end up behind someone at a railroad crossing and blow the horn, just for fun.

Back when I was working for a living, I drove the 405 FWY from the 118 FWY past LAX. There was (I guess) a short-haul trucker who more than once tooted his train whistle in the Sepulveda Pass when somebody did something stupid. That 4-horn setup ain't as much as a train whistle, though I'd really like to have one for my truck. I have a little air horn that sounds like a pipsqueak who wants to be a bully.

[70STOVEBOLT]

Originally Posted by Steeveedee

Back when I was working for a living, I drove the 405 FWY from the 118 FWY past LAX. There was (I guess) a short-haul trucker who more than once tooted his train whistle in the Sepulveda Pass when somebody did something stupid. That 4-horn setup ain't as much as a train whistle, though I'd really like to have one for my truck. I have a little air horn that sounds like a pipsqueak who wants to be a bully.

I paid $68 for the horns and I might have $10 in the harness and bracket I made. That's less than a set of stock high and low note horns. I will post pics after I get it all installed.

[HotWheelsFan]

Ha, I have used my horn in the tunnel on the 405 northbound to the 5 going north. When traffic backs up in the afternoon during the hottest summer days, you'll hear hear em.

Back then I used my 70 Monte Carlo as a commuter vehicle.

[heskahoka]

Originally Posted by 70STOVEBOLT

I recently got a set of 4 Cadillac 2-wire horns for my truck. Does anyone know if the stock horn relay will handle the amperage from the 4 horns, or do I need to add a relay or wire the horns in pairs and use two relays? I searched the web and cannot find a definitive answer.

I had the same question when I did my 4 Cadillac horns.

I think the stock relay would drive them, but was not sure on the wire capacity.

I ended up using an additional relay because it made the wiring simpler; it was easier to mount an additional relay near the battery to get the + and then run the relay + output out to the horns.
The normal horn relay was then then used as the switch.

[70STOVEBOLT]

With the 2-wire horns, the stock 14 gauge wire is fine. For the earlier one wire horns you would probably need 12 gauge.