Date: Fri, 20 Sep 2002 08:55:56 +0100 From: Max <maxdothodgsonnopsamotcodotuk> Subject: Re: 2002 Saab 9-3 AM Radio Noise
On Tue, 17 Sep 2002 00:40:22 +0000 (UTC), amesnopsamrak.demon.co.uk (Andrew Stephenson) wrote: >In article <slrnaocl1a.mh4.agreenbunopsam.nyx.net> > agreenbunopsamnet "andrewunix" writes: > >> 16 Sep 2002 14:50:09 -0700, helleraknopsamnet suggested: >> : [static on AM stations, reduced when brake is applied] >> >> Hmm, I wonder if it's related to the brake lamp wiring. > >Could be. If the wiring is carrying static from the engine area >back to the vicinity of the aerial, grounding it at the front by >working the brake could explain the temporary end of the static. > >Keep in mind that, for signals like static, the +12V rail looks >a lot like a ground, just as the 0V chassis does, so "grounding" >of static can happen both by connecting to chassis and to +12V. > >OTOH, if there is static on the +12V, due possibly to a high-res >battery and/or leads, you have another problem. And at the high >frequencies involved in RF interference, cables stop being simple >resistances; inductance and capacitance become important. > >Check for corrosion at all the connectors involved in the brake >light feed and the light (and holder) itself. An ohm-meter may >help. Relevant check: does the light come on as brightly as it >should? The original radio in my 9-3 did the same, but when I changed it for an after martket one (a Clarion) the problem went away. Perhaps the factory SAAB radio is more prone to interference than others.