Horn Problem (strong when car on; weak when car off) SOLVED!

[gunlak]

i have this weird issue. firstly, for about a year, I installed a set of Bosch EC6 horns by myself. I made my own connectors and it worked normally and didn't have any faults. except that it's quite unsafe that I just crimped a hot wire to the other horn coz I didn't want to splice the stock connector.

So I just had my horns rewired by adding a relay and proper wire gauges and encountered this issue. When the car is off, it'll only produce a weak sound but when the car is on, it'll work normally.

What could be causing this?

LINK TO VIDEO
https://www.facebook.com/gunlak/vide...1/?pnref=story

[gunlak]

can't get it off my head. even if it's almost midnight here. discovered that it's just bad grounding from the horns. coz the mounting point wasn't sanded down to bare metal. will do that in the morning.

[MetroMPG]

So that solved it?

[gunlak]

So that solved it?

yes. just a bad ground. i tried hanging a ground wire on the horn from one of the mounting points of my grounding kit as seen on the pic. it won't be permanent. just did that to try if it's the root of my problem. and it was.

[Daox]

Glad to hear you got it fixed.

[gunlak]

One more thing, is it normal that the horn doesn't produce 100% power when the car is off? I already fixed the grounds by scuffing the paint to bare metal around the mounting points and also added a ground wire there. Both horns now toot but it only sounds about 80% when the car is off.. when it's on, no problem. I also tried just wiring 1 horn, it blares 100% when car is off.

Does it matter if the fuse on the relay is just 10A? (a big red fuse) I read somewhere the Bosch EC6 runs at 16A.. before I ran a 15A fuse on the stock fuse box and it worked as it should.

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nevermind all of this. I just removed the f'in relay. it's just giving me headaches and running without one didn't pose a problem for almost a year I jerry rigged it. atleast now it has proper gauge wires and connectors.

[Daox]

It is normal that the horn would be a bit quieter with the engine off. With the engine off the battery is supplying ~12.7V or less. With the engine on, the alternator kicks the voltage up to 13.5-14.5V to charge the battery so you do get more power.

[gunlak]

It is normal that the horn would be a bit quieter with the engine off. With the engine off the battery is supplying ~12.7V or less. With the engine on, the alternator kicks the voltage up to 13.5-14.5V to charge the battery so you do get more power.

yeah that's exactly my first assumption. but ever since the installation of the relay, its like the horn has to take time to charge up before reaching 100% power.