Poor FM with rear heated window on

[blackscooby]

As it's just starting to get colder I used the heated rear window on my W203 estate for the first time.
When listening to the radio the reception becomes very poor when the heated rear screen is on.

As soon as I turn it off reception is fine.

Any ideas ?

Ta

Mark

 

[miro]

As it's just starting to get colder I used the heated rear window on my W203 estate for the first time.
When listening to the radio the reception becomes very poor when the heated rear screen is on.

As soon as I turn it off reception is fine.

Any ideas ?

Ta

Mark

If it stops happening when a 21W stop lamp is in series with the heater connection then you need a new rear windscreen.

 

[television]

If it stops happening when a 21W stop lamp is in series with the heater connection then you need a new rear windscreen.

MB say that joining the window up to a 18volt source for 20 mins does fix the problem, sometimes.

Malcolm

 

[flave]

As it's just starting to get colder I used the heated rear window on my W203 estate for the first time.
When listening to the radio the reception becomes very poor when the heated rear screen is on.

As soon as I turn it off reception is fine.

Any ideas ?

Ta

Mark

that also happened to me for a while..on my w203 sportcoupe.
eventually it disappeared. :\

 

[Uky]

This is not uncommon for cars with heater wires on the surface of the inside of the rear window. Eventually small cracks forms on the wires. It can be because of wear (bags, tools, etc) or from corrosion caused by moisture.

I have seen this phenomenon with other brands as well.

The cracks generate noise.

I have not heard about the method suggested by "Television" but it could be worth a try.

Just make sure that all connections to the antenna amplifier is removed (If that particular model uses the heater wires also as broadcast antenna)

 

[automaniac]

My W210 is exactly the same, and its apparently down to the fact that the rear window heater element has been damaged in the past. This is easy to see on a fogged up window as parts of the heating element dont work when its switched on. Only solution is to replace the rear screen or fit an aftermarket radio ariel to your car , not the best choice but maybe the cheapest.

 

[GazCaff]

MB say that joining the window up to a 18volt source for 20 mins does fix the problem, sometimes.

Malcolm

It's more than likely the current that helps rather than the voltage. I used to use (slight) excess current to "clean" low current systems of high resistance to bring them to within spec.