Have you checked the goddamn horns yet? Or are you going to continue ignoring people who are trying to help you?

 

Yes I checked the horn if it works. It’s getting power. When I sound the alarm. The horn does go off.

 

So yes. The horn is getting power. When hit my alarm button, the horn does go off. The relay does click.

 

Ok, first I want you to check this diagram:

http://www.nicoclub.com/service-manu...7_G35_Coupe/ww

Page 44, I linked the COUPE which "should" be the same as sedan, I don't know which you have. So the IPDM is right next to the battery and has a bunch of fuses and relays and such in it, as you can see from the diagram the horn signal can originate either from the IPDM OR the horn switch. The IPDM signal likely is triggered by the alarm system and the horn button on the steering wheel is shown as "Combination Switch (Spiral Cable)" on the diagram.

For the next step you will use a Digital Multimeter set to resistance (ohms) hold the leads apart from one another, whatever is displayed on the screen is "infinite resistance" meaning the circuit is not complete, now touch the probes, it switches to 0 ZERO ohms, meaning the circuit is complete.

You already know that part of the circuit is functional because the horn DOES WORK when you hit the panic button (or door lock from fob), what you need to troubleshoot is whether the "Combination Switch (Spiral Cable)" a.k.a. the "clock switch" circuit in the steering wheel is functional. Locate and remove relay E20 (Horn Relay) from the IPDM module, use a meter with a long probe (I sometimes stick a straightened and shortened paperclip into the socket to prevent damaging it with the probe on the meter) and measure the RESISTANCE (ground / ohms) at pin 1, you should have infinite resistance without the horn being actuated. When you trigger the alarm/panic/horn switch you should then see the meter switch to ZERO ohms resistance meaning the circuit is complete.

I suspect your Combination Switch (Spiral Cable) inside the steering wheel is damaged and no longer functioning.

The Combination Switch completes the GROUND for the relay, there will be no power going to it, you will simply unplug inside the steering column and check for ZERO ohms when the button is pressed. I have no idea where to find the pin layout for the Super Multiple Junction inside the cabin next to the fuse panel at the driver side kick but it could also be read from that point, wire (Green wire, Black stripe) same deal, ZERO ohms to ground when the switch is pressed. If the Combination Switch is ok then the issue is in the wiring between it and the relay.

While you are troubleshooting, ensure that fuse 35 (15Amp) is good, it should be considering you can get the horn to chirp though.

Hope this helps, electrical gremlins can be a bitch if you're not familliar with the steps.

 

I got a multi meter. I tested the ground wire that's in the steering wheel. I'm get around 7-9V when I tested it. I tried doing a direct ground the the green wire to the body, still got nothing.

 

Did you ever look at the electrical schematic diagram in the FSM for the horn in the link that I previously sent to you?

Telcoman

 

Hey! I'm having the same problem. Did you ever get this figured out?

 

 

Ok...thanks

 

Unplug the horn, stick the probes of a DMM into the harness and have someone push the horn button.

Got voltage? If no it's possible a fuse but likely the clockspring.

If you have voltage then the horn needs to be replaced.

 

I check the fuse and both relays... I check both horns... and I took off the steering column and probe the clock spring.. I got continuity from it when I press the horn and I put my probe in the terminal that connects to the clock spring and didnt get a ground.. so I felt that I had a bad circuit from that terminal... just to be sure I took it to a mechanic shop but he told me it was the clock spring.... I immediately thought ...hey did I diagnose this wrong... but I took the mechanic advise because what do I know..he does this for a living and I'm a novice... so long story short I ordered a clock spring and I install it and the horn did NOTHING... $40 diagnostic test gone to waste... so now I think I was right about being a circuit problem... and unsure about my next move because I don't want to waste anymore money.

 

 

Yeah I think that's what I'm going to have to do as well... Thanks for the feedback tho

 

Same issue here with my 2008 G35x.

The mechanic I took it too initially thought it was the relay, so we changed the fuse in both relay boxes. Horn still wouldn't work. Tomorrow morning they are going to try and put in a new clock spring I bought. Fingers crossed.

If this does not work, I'll try getting a new combination switch.

 

Did you ever find out what the issue was?