DigitalSynthesis

Ahhh... the saga continues....

Yesterday as I fired up my car and pulled out, I heard the horn honk. I thought I might have hit it by accident, but it did it again a few seconds later. So I thought it might be a short or an issue with the car alarm system. (oh, yah I have a convertible ) So I ran the door locks up and down a few times (seems to make the alarm system - TDS - reset or something... its a stupid alarm anyway... any tips on how to totally disable it?)... that seemed to take care of the problem. But today, as I drove out, it did it again!

And my alarm system goes off randomly whenever I lock my doors. I don't know WTF is going on, but I want to get rid of this STUPID alarm and know how to fix my horn. Does anyone have suggestions as to whether these two problems are related and, especially, what to do about my horn? I live in Atlanta and need the horn (manually operated)... but I could care less about the alarm system working since it doesn't anyway.

Right now my horn is completely disconnected so I can still drive, but I promise you, its scary w/o one...

Thanks much guys!

vaughnc

There several guys who could troubleshoot this for you. Post something on the southeast e-mail list or this website's southeast section.

So after the alarm has been activated, you unlock the door with the key. Then the alarm goes off?

Sounds like the "kill alarm wire" isn't being tripped correctly and the car thinks you've opened the door from the inside.

When I had my keyless entry wired up, he had to overcome this issue to keep the alarm from going off.

On the horn, if you just barely tap one of the buttons does it honk? How about if you shake the wheel does it honk?

DigitalSynthesis

Well, not exactly... the alarm goes off randomly without being triggered from the outside. It doesn't matter if its raining or sunny (so I don't think its a water short), or what the temperature is, it just recently started going off whenever it felt like it. The alarm still de-activates correctly (i.e. if the alarm is sounding and I insert the key and open the door, it stops sounding)... but it doesn't always arm, and when it does arm, it sometimes randomly goes off.

As for the horn, no I'm certain its not a steering wheel issue. I tried all of the above mentioned things. It only goes off when the car is in a gear, and moving, but it doesn't appear to matter what the motion is (e.g. jerks or smooth, turns or not it seems to be a fairly non-deterministic pattern).

You are in Atlanta too? Cool!

RylAssassin

dude that sucks but it must be funny as hell being in the car and having it honk randomly id be pissed too but ppl that drive around with you must think it hilarious

vaughnc

Have you been to an Atlanta RX-7 meet? Every thursday and quarterly events. We drove hotlaps on a racetrack last weekend.

Sounds like if you've done basic troubleshooting you'll need to check into the wiring. It's most likely the connector ends behind the doors/trunk, junction box, etc..

If it arms and sounds while your driving, then it's most likely a short in the connector soemwhere.

Of course you can always have Mazcare fix it for you, but if you want to do it yourself that's where I'd start.

One of the SouthEast guys might do it for a discount as well.

StarionX

Are you sure it's the horn, and not one of the alarms (low oil, low washer fluid, power steering etc)?

DigitalSynthesis

Okay, thanks! Yeah I don't know anything about the Atlanta RX-7 meetings... can you send me some info on that (probably PM is best so the mods are happy...)?

As for the alarm, I'd rather disconnect it entirely. Is there a way to do that?

I'm definitely interested in fixing it myself.

I'm probably going to run a fixed horn wire, from the horn itself to the steering wheel directly, so it bypasses the alarm system entirely. Hopefully that will work.

Icemark

Have you re-soldered your CPU and checked the hornm contacts in/on the steering wheel???

and what year???

DigitalSynthesis

Yes... I have done both. Its an '89 'vert.

Icemark

Then disconnect the alarm CPU and see if it still honks intermittently.

If it does, you have not repaired the CPU correctly or there is a broken or damaged contact on the steering wheel.

hawk 7

iTrader: (2)

I think the car maybe POSSESSED!!! Stephen King made a documentary about car possession called "Christine". You didn't name your car Christine did you, if you did that may be part of the problem.

vaughnc

sent you a personal message. E-mail me if you need more details - atlantarotaryfan@earthlink.net

DigitalSynthesis

Icemark - Did that. No honking. Horn doesn't work on the steering wheel though, either. The relay is on that jumper in the CPU.

UPDATE - I flicked the door locks a bunch of times, the alarm system finally realized I was trying to arm it, and since it started (sort of) behaving normally the honking appears to have quit after a brief test drive (down the driveway and back up). (Yes, I let it run for a few minutes so it doesn't flood)

The problem isn't "fixed" its just hidden for now. I'll get around to installing my OWN relay for the horn and removing the alarm system soon. No time now...

Vaughnc - Thanks for the PM I'll reply in a bit... I might be there, depends on how much homework I get done tonight.

Icemark

No, Not the CPU, but unplug the alarm CPU. Two different 'puters

DigitalSynthesis

Uhhh, in the 'vert that I have the alarm is built-in to the main CPU according to the FSM. The "burglar buzzer" connector to the CPU is an 8 or 9 pin connector at the top of the unit. It appears to connect to the exact same physical board as the main CPU connector, which gets the door lock interfaces that the alarm triggers off of.

Unfortunately, the horn relay control is in the same connection as the alarm connector, which means that it won't differentiate between a problem in the steering wheel and a problem with the alarm system. However, I recently took off the steering wheel and inspected the horn assembly, so I am quite certain the problem is not there. Good idea tho.

It seems (according to the FSM) that the alarm logic is built into the CPU.

Note, I am not confusing CPU with ECU, the CPU I am referring to is the elongated black box mounted on the driver's left hand panel beside the footpedals, next to the fuse box.

Am I missing something here?