phiruckus

Hello my fellow rx7c members,

Please let me start off by saying that i've searched and searched numerous times on this issue. i've learned a good amount and understand the horn system pretty well. Also, i own an 86' N/A hatchback.

Here's my issue.
If i don't here my relay clicking, it's probably my horn switch, right?

I also read that:
My issue here is that i dont have a green/orange colored wire. What i have in it's place a a Black/Blue? wire. i dont remember right off the back of my head. But when i tried grounding the backside of this wire, i popped the hazard fuse. And then, i just stopped lol.

Ive included this pic to show what i based my work on.


Ill also include a pic of the backside of the plug i have in my car later on today.

Thanks for looking and any input would be awesome as always! Thanks-a-mil!


Note: I forgot to mention that i've taken the relay out and sprayed some contact cleaner on the contacts and i've done the same with the "spring thing" on the back of the steering wheel.

cloudzero

iTrader: (1)

When you took the relay cpu out did you check the solder joints inside of it? Many times those joints break in there and just need to be re-soldered.

satch

iTrader: (1)

The Black/Blue wire is powered by the Hazard fuse w/constant power. If you were to measure voltage on this wire w/no key you would have found 12 volts. This would have told you not to ground out the wire w/o further investigation.

There are only three wires in the highlighted plug which relate to the horn relay in the CPU (focus on this plug rather than the one located near the horn switch). So, go to the CPU and identify the plug for the horn as depicted in the diagram provided and locate this Green/Orange wire.

phiruckus

I did, none were broken.

ahhhh so that's why that fuse "popped". but allow me to show you the picture I took of the plug that I believe is the one that goes with the horn relay and maybe u can tell me if im trippen or something.







So I'm thinking, and all I can come up with is two things. First scenario, this is the Green/Orange everybody is talking about, and I just misread that its on the top plug and not the bottom one.

And second scenario, The previous owner of the car took the Green/Orange wire out for some reason.

And to add a third scenario, I might be wrong all together hahaha.

jjwalker

It's the green orange in the big plug. It should go to ground when you test it with a multimeter and press the horn button. Connector F-04 is clearly labeled in the diagram, not the connector you have highlighted.

Connector F-16 is NOT at the CPU.

satch

iTrader: (1)

jjwalker is correct as F-04 is the plug connected to the CPU and it being the largest CPU plug. F-16 (plug you highlighted is found at the horn switch in the steering wheel).

phiruckus

ahhhh I see. somehow I misinterpret what I read. Thanks for the verification. Greatly prec'!!

Thank you also for your verification.

Question. So let's say I ground the Green/Orange wire and the horn goes off, that means that my horn switch is the problem? and if so, do I buy another horn assembly or could I just buy a horn switch somewhere?

satch

iTrader: (1)

You might be able to fidget w/the existing horn button to see why it doesn't work as it should.

pfsantos

iTrader: (1)

I've gone under the dash way too quickly in the past due to our cars' inherent nature in terms of the electrical system, and have learned to check the easy stuff first. Don't ask lol. A few quick questions:

1.a) Do the horns work when you apply power to them directly on the connector, using a long wire from the battery (+)?
1.b) If not, unbolt them and ground the horn housing to the (-) on battery. Do the above. Do they work?

2. Did you check that you get power on the wire to the horn?

3. Have you fiddled with any wires near the horns? Did you mess with the A/C system (stay with me lol), like the receiver/dryer or nearby, or did the A/C stop working at the same time? The pressure switch is nearby and uses almost identical connectors. Did that once lol. A/C didn't work at the time. Did some painting, and disconnected it. After painting, connected horns using pressure switch wires. Horn didn't work...tried everything, ended up running wire straight from relay to horns. Only found out a few years later (!) after recharging the system and compressor wasn't turning on. LOL

phiruckus

That'd be cool but I don't know what else I can fidget with to get it to work. it just seems dead to me lol.

1) yes they work with direct power from the battery.
2) do I do that by applying ground to the Orange/Green wire? if so, than not yet. I need another battery before I can check this. I pretty much fried mine the other day. don't ask hahaha.
3)I didn't mess with those wires but I'll see if I can swap those wires to see if it works or not. Cant hurt it by trying.

satch

iTrader: (1)

In the largest CPU plug the G/W wire must have constant voltage and the G/O wire needs a ground to sound out the horn. And the horn switch needs to be mounted properly to work or it will not transfer the ground signal necessary to activate the horn. Look at the diagram and if you look at the two horns you will notice that each horn appears to have two wires eminating from it when in fact there is only one wire connected to each horn. The wire which appears to drop down from the horn in the diagram connects to a horizontal line via a solid dot. This means the ground is supplied by the item being bolted to the body as there is no individual ground wire. Same thing goes for the horn switch as it only has but one wire, thus if the horn switch is not bolted in place there is no ground for the switch to pass on to the G/O wire when the horn button is depressed.

jjwalker

This is correct.

The easiest way to see if an item is grounded through its own mounting point is to look for the little arrows on the diagram. See the >> that look like that on the wires in the diagram? Those denote a connector or a junction. In the diagram, you will notice that the horns and the switch do not have these arrows between them and chassis ground and this is what denotes that these items are grounded via their mounting points.

pfsantos

iTrader: (1)

No. I mean put a test light or multimeter to the plug for the horn (unplugged) and have someone press the horn. You should get 12V when pressed.

You said the horns work when you send power from the battery directly, so that means (1) the horn itself works, and (2) they have a good ground.

My "2." checks if you get power to the horn wire, which I doubt you're getting, unless you had a bad connection at the horn plug.

After that, if u get no power at step "2." you have to make sure your horn switch and wiring works...as Satch mentioned, the horn switch grounds a circuit to activate the horn relay. Basically, pull out the horn switch and ground the connector what was connected to the switch. Let us know if that makes it work. Sometimes the hub/steering wheel or parts behind it (angle sensor) don't transmit the ground signal all the way to 'earth', meaning negative terminal of battery and frame.

Once those are checked you're basically down to resoldering the CPU, or having a bad relay inside.

sp0ngebob

iTrader: (1)

is your horn plugged in? i did all this junk only to find out they werent plugged in

pfsantos

iTrader: (1)

Went back to the circuit diagram.

Just to simplify what is being said...do these two things:

With the F-04 plug plugged in to the CPU:

1. Back probe and ground the G/O wire at the F-04 plug. Does the horn sound?

Remove ground you did in (1.), now...

2. Jumper (by back probing) the G/W and G/R wires at the plug. Does the horn sound now?