Delmeister

An interesting thread of the same name was started by Dutch2 and is located here https://www.rx8club.com/series-i-interior-audio-electronics-24/beeps-not-horn-when-remote-lock-unlock-107664/. However after 6 months the complexity has skyrocketed and unit is still not available.
If you share the above feelings, you can build a simple circuit while you wait for the completion of the more advanced version. It is shown in the attached schematic and will cost you about five bucks. It only has seven parts (including a socket for the IC and some mounting board for the components) and you only have to get under the dash in the steering wheel area.

Notes:

1. If you don't have a service manual you can get it in pdf format here http://www.hi-impact.org/ryang/modif...8_manuals.html. In those manuals the relevant diagrams are:
Page 58 in the electrical manual for the flasher circuit.
Page 212 of the body manual for the location of the flasher control module.

2. The circuit uses a 556 dual timer. The first timer operates as a one shot. The second just follows the input but inverted and also acts as a current sink. Under normal conditions the input is high and both timer outputs are low so there is no potential difference to drive the beeper. On locking the doors, the keyless control module sends a short negative going pulse to the input of the flasher control module. Both timer outputs go high on the negative edge of the input so there is still no drive for the beeper. The one-shot stays high depending on the time constant determined by the capacitor-resistor combination. Say this is 1.5 seconds. The negative going input pulse goes back high within about half a second. The second timer output also changes on that edge but goes low. Now the beeper has drive and it beeps. The one-shot goes low one second later and the beeper shuts off. Since the hazard warning switch is on the same input, it initially acts as the keyless input when it is depressed. However since it will presumably stay depressed for more than a few seconds, the one-shot times out before the trigger input is released and its output does not rise. It will act like the second timer and so there will be no driving potential for the beeper. The beeper can be made to beep if the switch is toggled fast enough.

3. You can get all the parts at RadioShack including a selection of beepers (search their web site for all the components). Note the polarity of the beeper in the schematic if one you select is polarized. Use a socket for the 556. It is able to source or sink about 200 ma. If you wish, you can replace the pot with a fixed resistor once you have decided on the tone length. Use one of those small printed circuit variable resistors if you plan to keep it in the circuit. You can get a bag of them at RS for a couple of bucks. The longest time constant is 2 - 3 seconds in the schematic but the capacitor can be changed to alter this. Note the polarity of the capacitor in the schematic since the one you get will probably be polarized.

4. Test the circuit by connecting the battery and ground leads to a power source. Also temporarily connect a resistor (say 10 K) between the input and the battery positive. Rotate your pot to put maximum resistance in the timing circuit. Now momentarily ground the input. The beeper should beep, and the duration should be adjustable.

4. Before you do any splicing in the car verify that the positive terminal on the flasher control module is always positive, that the negative terminal is always negative, and that the input is high. If you can, activate the remote door closure and verify that the input goes low momentarily (may be noticeable with digital multimeter but best done with a scope or possibly with the older needle type meters). Activate the hazard warning switch and verify that the input goes low. Turn off the switch and short the input to ground. This should have the same effect as activating the hazard switch.

5. As you may have guessed, I actually haven't built or installed this circuit . However I did run a SPICE simulation of it. If you decide to take your chances on it, please let us know how you do.

P.S. The horn can probably be used as a buzzer if it is toned down with a resistor. If anyone wants to try placing a resistor in series with the horn to see how it sounds , the horn circuit is on page 62 of the electrical manual.

SC-ed

What if you connect the beeper to constant +12 V and get the negative pulse from the keyless control module. It's simple and should beep.

Delmeister

- The output of the keyless control module is directly connected to the hazard warning switch, so the beeper would beep constantly when that switch is activated.

- If you did connect the beeper the way you suggest, you probably should go through a transistor, since the output of the keyless control module may not be capable of driving any significant load.

- There is no control of the beeper on time.

nolz

If you did it that way, would there be a way to alter the buzzer on the board to only "chirp" for say 2 seconds before it disabled itself until it was reset?

This way when you turned on your hazards it would in fact still chirp, but it would only happen for 2 seconds, then again once u turned them off and back on... but unless you're using your harzards daily it wouldnt be an annoyance... but would solve the problem...

Delmeister

The attached circuit eliminates the hazard switch interaction, but it does mean that the keyless control module input wire has to be cut and a diode inserted into the circuit. There is nothing wrong with cutting wires but I'll have a look at this later and see if there's a way without cutting, and more along the lines you suggest (i.e. short beep on hazard activation).

Also there seems to be no way to use the horn as a beeper by softening it up with series resistors. It draws about 10 amps average, and even 1.0 ohm in the line will stop it from operating. If it is not operating it is almost a short circuit. At half an ohm it draws about 20 amps. Drop the resistance just a bit more, and it turns full on.

Delmeister

OK, this circuit doesn't require wire cutting. The beeper will be on for the length of time the keyless control module is activated (presumably for as long the the taillight flashes on remote lock, but this needs to be checked), and for slightly longer when the hazard warning switch is turned on.

nolz

For those of us not small electric minded, could you provide a list of the materials needed, sourced from someplace we would all have access to like a RadioShack, and instructions on building the circuit? Make this an actual DIY as I am very interested in this, as the more advanced model is getting a little out of hand, I'm interested in just this functionality.

Delmeister

I was hoping that someone would be interested in performing a few experiments, build the circuit and install it. In effect take over the DIY with pictures and all. I'm too lazy. I'll build one when all the groundwork has been done (what buzzer? where should it be positioned? what timing? where is the flasher module actually located? what are the actual wires to splice?). Ideally, someone who is interested in kitbuilding and has some electronic knowledge should do the prototyping. But really only the interest is required - I or others can provide any electronic assistance when needed.

There is still the question of the beeper. RadioShack has a few http://www.radioshack.com/family/ind...032058.2032230. I don't know if you can test these things because their components are usually contained in sealed packages. You would have a better chance of testing these in an electronics components store where the parts are usually unpackaged and in a bin.

If you wish to be the first to put this together, I would suggest you get something like this http://www.radioshack.com/product/in...entPage=family so you can bench test your circuit before soldering it up. You can still assemble this circuit before deciding on a beeper. Just put your multimeter or an LED (with 1K series resistor) across the output.

I would recommend the circuit below. The parts from RadioShack are:

R1, R2, R3 (47K, pack of 5) http://www.radioshack.com/product/in...entPage=family

C1 (22uF) http://www.radioshack.com/product/in...entPage=family

Q1, Q2 (PNP, pack of 15) http://www.radioshack.com/product/in...entPage=family

Circuit Board http://www.radioshack.com/product/in...entPage=family

GlenAnderson

Del- can you label the transistors, B,C,E?

I have some basic knowledge of electronics but have never seen a transistor with the arrow pointing in the direction you show it.

Thanks,

Delmeister

these are pnp transistors. the emitter has the arrow, the collector is directly across it, and the base is the line that goes out at right angles to the vertical line (i.e. between the emitter and collector.