bmw old alpine alarm sound on dei 554r

I always wanted the original BMW Chirp alarm for my car (99 bmw m3).... its the one you always hear in the movies... Here are the tones http://www.youtube.com/watch?v=_ht_C5s0EGw My alarm is a Valet (DEI) 554r alarm and it works great, I got a siren from an old e36 stock OEM alarm (made by alpine?) part number 82 11 1 467 019. I wired in the BMW siren to my alarm, but it doesn't work correctly. Problem is that the unlock lock tones are not long enough to trigger the alarm. Lock gets me no sound and unlock gives me one faint chirp. If the alarm is triggered it works perfect and I get an alarm sound. I am assuming the DEI alarm is not sending a pulse that is long enough to trigger the siren to put out the tones... Can anyone think of how I can get around this? 555 timer? relay.... something?    I already looked at my alarm settings there is no way to adjust the 12v pulse duration for the lock and unlock. Looking for someone that is smarter than me for this project?

Use a DEI 528t timer, feed it via diodes from the lock and unlock wires, that will change it from 0.8 secs to however long you want it. See diagram:- siren_sound.bmp Notes join a 1N4004 diode from lock and unlock to BLACK/ white, Join red to brown to 12v+ constant and use a 5amp fuse, Yellow from 528 to siren, Orange wire don't use. Blue loop, don't touch.

WOw thats awesome thanks,,... never seen one of these... I will try it. Have you tried this setup b4

Also why does it need to tap into the lock/unlock output? Should it just be able to detect and increase the pulse based on the single or double pulses from the alarm siren output? Also with this can I still unlock the car with the stealth mode option (no siren chirp?)

No, wiring it from the siren output will double you pulses! Also slightly simpler my way. If you have any queries with/about the alarm or R/S part don't hesitate to post, I wrote the definitive install guide to the E46.

will this still keep the stealth (no alarm unlock option)?

If you mean silent arm/disarm no. Also if the alarm has comfort control you won't be able to program that either.

I really wanted to keep the silent arm, disarm.. You dont think there is anyway to keep this by just using the pulse that comes from the siren output?

your alarm can be changed from a 0.8 second pulse to a 3.5 second pulse by entering the #1 menu and changing 1-6 from the default 0.8 second to the 3.5 second

I believe that 1-6 is only for the door lock pulse.... and not the siren pulse.