Radio antenna signal amplifier?

[striker600]

Should my car have a radio antenna signal amplifier fitted? there is no mention of it on th mb fuse card.If so where can i find it and is it possible to test it? Radio reception is very poor since i had rear tailgate screen replaced yesterday.
See this related thread for further info.- HELP! heated rear window exploded
Any information&help will be appreciated.

[Stratman]

I don't know about the W203 (but a Haynes manual for it is imminent ) but in the W202 estate, there is an aerial preamp in the roof behind the top of the D-pillar on the passenger side.

It's far more likely that you have a poor connection after the fitting of the new rear screen. Look very carefully at the heating elements in the screen. You will see that a couple of them don't seem to be connected to the rest. These are the FM aerial (on the W202). The 202 estate has a noise supressor fitted and it's possible that this hasn't been reconnected, that's if you have one. Remove the trim panels from around the rear screen and carefully check that all the connections are clean and tight.

As I said, this applies to the W202. it shouldn't be radically different on the W203, but there is the new Haynes to look forward to.

[chrisneal@clara]

Hi, I think I have a similar question ref radio signal being poor, but I am a newby to this site so may be posting in wrong section. My E Class 210 Radio (Merc Audio 10) has poor quality reception and someone mentioned I should get the amplifier checked, just wondering if you received any useful advice/info from the posting and if any other links were suggested?
Thanks
Chris.

[striker600]

Originally Posted by Stratman

I don't know about the W203 (but a Haynes manual for it is imminent ) but in the W202 estate, there is an aerial preamp in the roof behind the top of the D-pillar on the passenger side.

It's far more likely that you have a poor connection after the fitting of the new rear screen. Look very carefully at the heating elements in the screen. You will see that a couple of them don't seem to be connected to the rest. These are the FM aerial (on the W202). The 202 estate has a noise supressor fitted and it's possible that this hasn't been reconnected, that's if you have one. Remove the trim panels from around the rear screen and carefully check that all the connections are clean and tight.

As I said, this applies to the W202. it shouldn't be radically different on the W203, but there is the new Haynes to look forward to.

UPDATE.
Took car back to windscreen company yesterday(fri).They diagnosed a break in the new window element.Having a replacement fitted this coming wednesday.
Mine is the Audio 10 head unit.When i remove the black coax round pug from screen it makes no difference to fm reception(still crap).When listerning to AM stations the reception is perfect,even when this coax plug is disconected! why is this?
Stratman,thanks for the info on the aerial pre amp,but its probbably not worth me testing/replacing this untill i get another new HRW fitted on wednesday.
Just wondered if its possible when the old heated rear window exploded,if it could damage the aerial pre amp?
Another point,i dare not use the hrw just in case this one exploads,but i did test the voltage across the two wires that connect to the heating element.
With engine switched off i got 12.2 V. With engine running i got !4.65 V.Would this higher voltage cause the HRW to pop or Is this 14.65 V ok with engine running,or should it stay at 12 volts with engine running?

[striker600]

If anyone who has a W203 estate could disconnect the two wires to their HRW & measure the voltage(with engine running) and you get around 12 V,then i would know i have to much voltage with mine at 14.65 V.
Thanks.
Andy.

[Stratman]

Thw AM aerial in the estate is in the rear quarter light so won't be affected by the HRW.

With the engine running 14.65 Volts is perfectly normal. It shows that your alternator is working properly. It may drop a bit when the HRW is switched on but again, this is normal.

Radio waves are funny things and nobody really knows how they work. If it's any consolation it's very unlikely that your preamp is faulty. What will pay dividends is to carefully check every connection in the aerial system. Make sure they're clean and tight and while the HRW is being replaced check the noise supressor as well.

[striker600]

Originally Posted by Stratman

Thw AM aerial in the estate is in the rear quarter light so won't be affected by the HRW.

With the engine running 14.65 Volts is perfectly normal. It shows that your alternator is working properly. It may drop a bit when the HRW is switched on but again, this is normal.

Radio waves are funny things and nobody really knows how they work. If it's any consolation it's very unlikely that your preamp is faulty. What will pay dividends is to carefully check every connection in the aerial system. Make sure they're clean and tight and while the HRW is being replaced check the noise supressor as well.

Stratman, i will check every connection in the aerial system tomorrow.
What is strange though is when i remove the aerial plug from the HRW and then touch it to the left of the hrw aerial connector (about 25mm away from the break in the element), the fm reception is perfect.

[striker600]

just checked the connectors associated with the aerial & amp.All seem ok except for the round plug that fits on to the HRW aerial stud,looks like the center coax core has been soldered on to the round metal plug and the outer (criss crossed) braid wire is not connected to anything.But as i said in post#7, if i touch this coax plug to the left of where it connects on the HRW element the FM reception is perfect,so i can assume the aerial amp is working.and that the coax cable is ok.
Having said that i have visited my local mb dealer who has ordered two aerial amps as they are not sure which one is for my car(even with having the chassis no.and 2 guys visualy having a look at my car! Also they dont no yet if the coax cable (amp to HRW aerial socket) is sold seperatly.Parts due in tomorrow.I will post a update in due course.

[striker600]

Update.
Had a new HRW fitted on fri(2nd one) as first one had a break in the heating element.FM radio reception is much improved,back to normal.
The coax cable from radio signal amp to HRW connector has not yet arrived at MB(been on order now 10 days!) The bloke at MB has e mailed their technical department as nothing shows up on the dealers parts department computer.If it ever arrives & is resonably priced i will have it as the outer braiding on mine looks a bit tatty.