Horn Not Working

[Miatamaniac92]

Well my car hasn't been inspected since Feb. when I was activated. I can now finally bring my car on post so I need to get it inspected.

Problem is I forgot to hook the horn back up when I installed the intercooler. I noticed this today when I was troubleshooting my months long horn problem. Seemed like a simple solution, unhooked the horn off my brothers junk Miata and hooked it up. Plugged in the one wire and bolted it up. Pushed the horn button and it worked.

The big but is it won't work with the key turned though. Is this some kinda grounding problem?

Chris

[tailchaser]

The big but is it won't work with the key turned though. Is this some kinda grounding problem?

Chris

Dayum... didn't realize Tom McGrath installed your intercooler...

Did you put a relay on your horn?

[Miatamaniac92]

LoL

It's a stock horn.

Chris

[tailchaser]

LoL

It's a stock horn.

Chris

Couldn't remember if you'd had air horns in at some point. I can't think of anything that would affect key on vs key off without a relay involved.

[channelmaniac]

OUCH...

Looking at the wiring diagram for a 92... It goes from the battery to the main fuse... and from the other side of the main fuse it goes to the BTN fuse... this feeds the stop fuse... which in turn feeds the horn relay (and stop lights!)...

There shouldn't be a reason for the horn to stop working when the power is on unless you have some wiring splices in place somewhere. Do your brake lights work with the key turned on?

RJ

[sammm]

The horn itself could be broken...happened on my '92. Go buy a cheap Fiamm somewhere and wire it in.

[Billy Blaze]

I have my original somewhere I can try and locate, if I find it I will give it to you.....just let me know if you would want it before I go sweat in the shed looking for it...lol

[Miatamaniac92]

I guess I'll get some Dual Air Replacement's or the loud PepBoy's version. Anyone have some strong recomendations for cheap and easy to install?

Chris

[sammm]

I picked up a pair of hi-lo tones at Harbor Freight. Much better than stock (which wouldn't take much)

This is similiar to what I installed in my '92...
LINKIE

[channelmaniac]

I installed a cheap set of the Wolo air horns from Pep Boys on my 03... Sure does get the attention of the Soccer Moms and folks that have their cell phone up certain orifices... you know the types.

They sound like this and the installation on my Miata went like this...

If you get air horns, make sure you run a separate power wire (with a fuse too!) to run the compressor. The fuse for the horn also runs the brake lights - you DON'T want to blow that fuse when stomping on the brakes & hitting the horn at the same time.

I have spare wire and connectors left over from my install if you need them...

RJ

[black roadster]

If you get air horns, make sure you run a separate power wire (with a fuse too!) to run the compressor. The fuse for the horn also runs the brake lights - you DON'T want to blow that fuse when stomping on the brakes & hitting the horn at the same time.

I know you are more of an electronic guru than I am but I've always just replaced the 10a brake/horn fuse with a 20a. No additional relays, just the stock horn power wire to the + on the compressor and a ground wire from the body to the - terminal on the compressor. I have done this on several Miatas with no problems. My current setup is 4 years old. YMMV

[channelmaniac]

I know you are more of an electronic guru than I am but I've always just replaced the 10a brake/horn fuse with a 20a. No additional relays, just the stock horn power wire to the + on the compressor and a ground wire from the body to the - terminal on the compressor. I have done this on several Miatas with no problems. My current setup is 4 years old. YMMV

There's always a risk of damaging the wiring harness (melting things, cooking connectors, etc) when running more current through it than it was designed for. I felt better by running separate wires for it. Like you said, YMMV... but since my car was maybe a year old when I did that, I went with the overengineering solution.

RJ

[Titus]

There's always a risk of damaging the wiring harness (melting things, cooking connectors, etc) when running more current through it than it was designed for.

That's always fun... when I was 17 and driving a mini-truck, it had an amplifier under the seat installed by the previous owner. He had soldered the power into the back of the fuse box. I managed to ground the wire as I ran pinched it adjusting the seat. Turned the whole back of the fuse box into molten plastic. Mmmm, I can still remember the smell!

[tailchaser]

Sometimes it's not ever your fault... Happened recently to someone I know... Just thought I'd share...

Saturday while driving down the road my 2m radio turned off on me.
Thinking I had perhaps blown a fuse I was a bit concerned but did not
stop. When the SMOKE came pouring out from under the hood and into
the cab of the truck I did pull over. Some how my positive lead from
the radio to the battery had shorted out and was in meltdown. I could not touch the #8 wire since it was glowing red.
As I was getting ready to start digging in my toolbox another truck
stopped and asked if I needed assistance. He has a pair of wire
cutters handy and I cut the wire at the battery.

I was a bit perplexed as to why the fuse had not blown and decided to
dissect the blade type fuse holder once I got back to the house.
Before I opened it up I checked it with an Ohmmeter with and without
the fuse installed. It had direct continuity with and WITHOUT the fuse in place.

The inline fuse holder I was using was one of several that Tanner’s
had on clearance about a year ago. I had 3 left in the drawer and
checked those as well. 2 of the 3 have direct continuity through them with out a fuse in them.
I basically had no fuse protection at all in my mobile installation.

The fuse holder I am referring to is black in color with a #10 wire
coming from each side for hookup. It also states on it that it was
made in China. Not sure if this was isolated to the batch that was on
clearance or not, but I urge everyone to check to make sure that when
the fuse is removed it actually breaks the connection in the line.
Had this short occurred while I was not in the truck I feel confident
that substantial damage would have occurred to my electrical system.

I am now running an inline fuse holder that is made of thin plastic
and uses the old style BUSS fuse. Now if the fuse does not blow at
least the housing will melt quickly and break the connection.