Hi All

I have a radio inteference problem....

My 928 S2 has always had problems with electrical interference with the radio on FM stations (in the UK) but lately it seems to have got worse.

Recently i have noticed that its a LOT worse when my foot is on the brake pedal (auto) so for example when i get to a junction and hold the autobox on the brake the radio is much worse, and once i move off it improves when i release the pedal and i cannot quite figure out why and more importantly how to fix it..?

The radio/cd unit is only around 4 years old and in good condition...

Any advice or help greatly appreciated

All the best Brett

 

your grounds are dirty for the radio and the engine charging system

 

Have you checked and cleaned your ground connections for the radio? Is the stereo connected to an external amplifier?

 

Hi

I understand all the answers and all my grounds have been done....so not that...

Its the brake pedal electrics affecting it so badly I do not understand... the pedal switch works perfectly, but COULD it cause interference on its own ?

Would you think a new switch would make the slightest difference ?

All the best Brett

 

Where is it grounded to? Are you using the OEM ground line from the original stereo?

Where is the power coming from? Using the original or did you run your own to the fuse panel?

Do you get any noise that changes with engine RPM?

Is the noise there even if the stereo is turned off?

 

A bad switch could create RF noise if the contact is bouncing and arcing.
Also, any chance that the antenna wire runs next to the wires for the break switch? Noise on the 12V could couple onto the antenna (or preamp lines if you use an external amp, but that would effect all the audio modes of the stereo).

 

I can' resist- This is your dashboard wiring, plus all that NAWS stuff and you only have radio noise recently? I'd say you've been lucky so far...

Seriously, though, I'm having the same sort of problem with the blingy stereo in the GTS and haven't figured it out. If your noise is only from the radio and not when playing CD's then clearly antenna related, but you say it's always been a problem for 4 years. Made any additional dash mods in the interim that would potentially made it worse? Where's the antenna routed on your car?

 

What type of interference ? Is it a whine that alters with engine rpm ?

 

Hi John

No whine or rise/fall with engine revs, just general hissing type interference...

Wiring to radio is 928 original, and aerial is the standard aerial in screen one....

All the best Brett

 

Sounds like a poor signal strength, maybe no power to the in-screen amplifier

 

Interference on the radio most likely coming in through the antenna input. It may be that your grounding is the antenna is poor, IE it isnt shielded well. You might want to follow those connections back. Also, if you car had a antenna amplifier, you might want to check that as well, IE does it have or not have power? Is the amplifier grounded properly, etc.

Joe

 

Hi

I didn't realise I had an antenna amplifier, I will check to see if its powered and the connections are good, and thanks all

All the best Brett

 

What about the suppressor relay? Isn't that it's purpose, to suppress electrical interference to the radio? Can't remember which relay that is; check the 928 Specialists website and make sure yours is tight. Unfortunately, I believe that's one of the more expensive relays so hopefully this won't turn out to be your problem.
Dan

 

The purpose of that device is to supprress the large spike that results from switching the Aircon compressor clutch solenoid. That device would not affect the radio.

 

Hi

Has any got a picture and rough location of the aerial amplifier as I have just realise I wouldn't recognise it lol ?

All the best Brett