I have the factory AM/FM Cassette unit with equalizer and Gain unit on my 93 Bonneville SSE. anytime a cell phone is used or I pass someone on a cell phone my speakers start emitting a very loud MORSE-code like interference noise. The interference occurs regardless of uning the radio, the cassette or even using my iPOD through the DLO branded Transpod. Turning down the volume does not help, changing frequencies does not help, but if I power off the unit, it goes away. Any suggestions out there? Could this be one of those grounding problems? :?:

I GOT THE SAME PROBLEM!!!.....Its so odd.....It only does it with some cell phones though.

My 92 does the same thing but a little different than what your describing.
I have the same deck with the amped system, but mine only gives off funky noises when I'm recieving a call or making a call, when this happens usually I just hit the power on the stereo.

I noticed you said "It only does it with some cell phones".
This could be the differences between GSM & TDMA phones. Different providers use different networks & phones.
GSM'* only transmit a signal durring calls or periodicly to stay connected to the network. TDMA'* are always transmiting & recieving.

This is just a guess on my part, as to why it only happens with "some phones".
My phone is on a GSM network, I should try it with one of my friends phones in the car to see how it is with a TDMA phone in the car.

Does anyone know if this still happens once you change the head unit to an aftermarket ?

Dutch

I gotta believe this is outside interference from Cell phones of some type, probably introduced thru the antenna lead. So, I am going to try to disconnect the antenna coax feed from the back of the head unit and then play a cassette or my iPOD thru the speakers to see if I get any interference. Will post results later.

Nope it does not have to do with the antenna. Mine is disconnected/broken. I think its something with the wiring of the rear speakers somehow picking up the interference.

I talked to an electrical engineer today and he concluded the problem was caused by GSM-Based Cell phones.


He said if you put your GSM (certain GSM only) compatable phone near a speaker it should make noise

I've never noticed that. How common are GSM phones?

Pretty common now. And something else I noticed...newer FACTORY car stereos will not pick it up (at least not on my Malibu Maxx)...I dunno if the speaker wire shielding is better or if there are noise-rejection circuits onboard the new stereos.

But my new Kenwood still picks up the initial handshake (the Morse sounding noise) and the connection (the continuous noise). Which is actually kinda neat, since I know I am getting a call even if I am blasting the volume and would not know it otherwise

Yeah, I have noticed the interference from a lot more than just car speakers though. TV speakers, portable speakers I use with my laptop, some alarm clock speakers, even the speakerphone on my desk at work. Seems to interfere most often right before the cell phone is about to ring. Its freakin annoying! Only thing I have found to help is to move the cell away from the speakers, head unit, mp3 player, or whatever else is hooked up.

Very strange. I have the problem on my '96. I can tell when I'm about to get a phone call atleast 10 sec before it rings.