Airhorn install ... not enough "juice" ?

[Wyvern]

Hi ..
I installed some Fiamm air horns using the OEM wiring. (Hi Low electrics came out ... they worked fine ...I just wanted the Air horn)

The Air horns work but are anemic ...Take a moment to pump up and not loud at all.
If I direct wire the horns to the battery ...they work GREAT !

I do know the OEM wiring has a relay to the horns...
How can I get more amps to the horns? Think the OEM is rated at 20 amps, would have thought that was plenty.

Should I rewire a higher amp relay ... OR ???

Thanks for any insight / suggestions

[Evans, Marv]

Can't necessarily help with wiring, and it does seem like 20 amps should be enough. Maybe there is another issue. For some reason, I've always wanted to install some semi truck sounding air horns in my car. Let us know how it turns out.

[WilsonTC]

Could be a grounding issue. Have you tried a separate/additional ground from the horns to the chassis?

[WolfeMacleod]

Originally Posted by Evans, Marv

For some reason, I've always wanted to install some semi truck sounding air horns in my car..

Same here, but I want to do an "Aaaoogah" horn.

[kodioneill]

FIAMM horns suck, period.

In the 70's they were a good product now they aren't loud and they fail within a year.

[Wyvern]

Originally Posted by kodioneill

FIAMM horns suck, period.

I thought they "BLOW" not suck ... maybe I have them wired backwards.

[Por_sha911]

Originally Posted by wilsontc

could be a grounding issue. Have you tried a separate/additional ground from the horns to the chassis?

+1

[rpidduck]

I have Fiamms in my 68, installed that year by Porsche Vienna, Austria. They continue to work great, but can't provide insight into wiring. There is an under dash switch installed so that I can switch between anemic factory horns and air horns. This to accommodate any re-export issues into California. Never a problem. Richard

[porsche930dude]

im thinking the factory wires are probrobly insufficient and maby bad connections

[donporfi]

Check also the relay and all the connections for dirt or rust.

[Wyvern]

today I did some testing ...

A jumper wire from + on battery to the + on Hom pump >>> works GREAT
(this I will assume tells me I have plenty of power in the battery AND that my ground is good)

Removed the relay and used the same jumper wire from terminal 30
(should be 12 volts direct from the battery)
to the + on horn pump ... weak horn ...

I am going to say the 12 volt supply to the relay socket is "compromised"
I removed, cleaned and, re attached the 12 volt connection from + of battery ...
still weak ...

[DanielDudley]

Use the hot wire going to the horns to run a new relay to direct fused power directly from the battery. Those horns need a lot of juice from a big wire.

[richde]

What you want are Supertones, which come with the required relay, IIRC.