I have problem with radio signal when motor is ON, if I turn Off motor signal is average/good. I dont have accesories connected to the car which could cause this problem. I tried to change diversity module but the problem persist.

It would be helpful if you described the "problem" you are having with the radio signal when motor is ON. For example, is there static or buzzing heard through the speakers? Is it related to the ignition, where the interference varies with engine speed? Is it more prevalent when the brake is applied?

Also, which radio option do you have in your vehicle? If not sure, check your vehicle options using this page (just enter your VIN):
https://www.etkbmw.com/bmw/EN/vin/decoder/online

George

 

I have simple factory bmw professional radio.
When I put key to car I have good signal and I can reach a lot of channels.
When I start the engine or driving I have very poor radio signal and I can hear only few stations which have their signal towers near.

 

I would swap your battery. A battery can have a dead cell and still start your car. Your battery is also the biggest noise filter in your cars electrical system. Check your connections at the battery too. I've seen faulty battery's and bad connections cause noise Good luck.

 

Check both the resting battery and running alternator voltage for
starters.

 

Radio Antenna Signal Weaker w/Engine Running



Do you have any circuit diagram/schematic for the antenna system, particularly the antenna amplifier??

Sounds like there is a reduction in the antenna signal when the ignition is ON (or at least the engine is running). If anyone has the circuit (NOT in Bentley) can you identify anything that is supposed to change in power supply to the antenna amplifier between ignition on & "radio mode"?

OP, does the problem happen when you put key in slot & just press start WITHOUT foot on brake (just ignition ON without motor running)?

George

 

When I put key to hole and radio starts to play signal is good, but when I start engine I have bad signal, I checked battery today but it seems to be ok.

 

Today I finally found the problem. I removed my white angel eye led(H8 40W 8LED) and installed original yellow lights and radio signal is good again. Finally