BMW DIY Poor Radio Reception Repair, AM and FM, E46 3-Series and Other Models

A common complaint on later model BMWs (those with the amplified “diversity” antenna systems using the rear window defroster grid, as well as “shark-fins”) is poor radio reception.  This problem can show itself on both the FM and AM bands and is typically progressive.  The cure is relatively easy to implement.  Check the steps below, shown on a 4-dr E46 model (3-series 99-05).  Other models will be similar.  The applicable Bentley repair manuals will detail the C-Pillar trim panel removal on other BMW models.

DeoxIT contact enhancer:
DeoxIT Contact enhancer

Other DeoxIT products:

DeoxIT Contact Cleaner

Non-Marring pry tools:

Non-marring pry tool set

Bentley repair manuals:
Bentley Repair Manual E46


1)  On the driver side (left side): Pull back the door gasket, along the C-pillar.

2)  Use a non-marring pry tool to pry the C-pillar trim cover loose.  There are two clips at the upper end of the cover (see the following photos).  Unplug the light harness plug and then pull the cover upward to fully remove it.

3)  You now have access to the antenna amplifier and the window grid connections.

4)  Unplug and remove the window grid connector harness.

There is one snap clip at the upper end of the window grid harness plug.  Carefully pry the clip away and push the plug assembly upward to remove.

Connector plug on window with harness plug removed.

Window antenna harness plug.  Clip is show at pinky finger.

Disconnect window harness from amplifier.

Window harness removed.

4)  Disconnect the antenna output and power connector plugs from the amplifier.

5)  Apply the DeoxIT drops to each terminal connection on both ends of the window harness and each of the antenna and power terninals.

6)  Reassemble the window connector harness and the output and power plugs.  Reinstall the C-pillar and the door gasket.

7)  There is another unit under the passenger side (right side) C-pillar.  This is a radio frequency trap, or filter.  Perform the same work with the DeoxIT on this unit.

Bavarian Autosport

1 Series Conv - E881 Series Coupe - E823 Series 92-98 - E363 Series 99-05 - E463 Series Conv 07-13 - E933 Series Coupe 06-13 - E923 Series Sedan 06-13 - E903 Series Wagon 06-13 - E915 Series 89-95 - E345 Series 97-03 - E395 Series GT 2010 on - F075 Series Sedan 04-10 - E605 Series Sedan 11 on - F105 Series Wagon 04-10 - E615 Series Wagon 11 on - F116 Series Conv 04-10 - E646 Series Conv 10 on - F126 Series Coupe 03-10 - E637 Series 88-94 - E327 Series 95-01 - E387 Series Hybrid 11-15 - F047 Series Li 02-08 - E667 Series Li 09-15 - F028 Series 89-99 - E31Tech TipsX3 04-10 - E83X3 11 on - F25X5 07-13 - E70X5 99-06 - E53X6 07-13 - E71X6 Hybrid 11 on - E72Z4 09 on - E89Z4 Coupe 06-08 - E86Z4 Roadster 02-08 - E85

6 thoughts on “BMW DIY Poor Radio Reception Repair, AM and FM, E46 3-Series and Other Models

  1. If it’s that simple, why can’t car manufacturers do it?
    Is it too fiddly or is it because they can sell more products when car buyers want to get better reception.

    1. The oxidation of the contact terminals is a progressive issue. At initial assembly, all is fine. As the vehicle ages, the electrical contact terminals oxidize and this reduces the electrical contact. The radio antenna signal is very low voltage and current. Therefore it is quite susceptible to interference due to the oxidation.

      The DeoxIT will not only clean the terminals, but it leaves a protective coating to prevent future oxidation or corrosion.

  2. My 1996 328i Convertible has the same problem (I think). FM reception is especially bad. It sure would be nice to be able to pull in some good old FM tunes while driving down the road with the top down. Is there a similar fix? I have the “whip” antenna on the back next to the trunk. Do you think it’s the connections? Could it be the amp? Thoughts?

    1. The antenna on your E36 convertible (as well as the 318ti and the Z3 models) is different from the defroster grid applications. However, if you are experiencing reception problems, then we would suggest that you perform a similar DeoxIT application. You will have the connection where the antenna mast screws to the amplifier unit and the connection from the amplifier to the antenna cable (inside the trunk, behind the side trim panel).

  3. I have been going insane the last year trying to listen to the radio with the defroster on…I am glad you guys posted this. I appreciate you folks identifying these common problems so we can fix them. Thank you.

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