I've just posted this in electronics, just thought I'd try it here as well....

I've just fitted an FM Modulator to my car in order to use my MP3 player with the 2002 head unit. I have installed it in the boot (trunk). The power comes from the wire that supplies the aerial booster. The modulator plugs in line , between the existing aerial lead and the aerial.

The problem I have is, that when the modulator is powered up the radio reception is almost non-existant (the MP3 works great though!). The only way to get the radio reception to work is to disconnect the power to the modulator and then of course the MP3 doesn't work.

Does anyone have any experience of this type of modulator? Is it meant to cut the radio reception, perhaps to reduce interference from other broadcasts? Any suggestions for getting round this, other than fitting a power switch? Would it make any difference if it was installed near the head unit instead of near the aerial? Do I have a faulty unit?

Thanks in advance

 

Have you maintained the connection to the existing aerial amp when connecting it up? Where and how have you grounded the FM modulator? It ought to be transparent to all frequencies other than what it outputs??

If I were you I'd not have messed with the OEM wiring loom and would have tapped a line from the switched power output in the fusebox to power it up and used the ground bolt next to the fusebox. Bit late for that advice now though

Tif

 

Tif,

the power is maintained to the amp, I have checked. The earth is good, I checked with a voltmeter. Interestingly, if I disconnect the power to the amp AND the mod, the radio still works fine. It definitely seems to be the modulator blocking the signal. I'm going to see if I can get some sort of aerial connector that will allow me to connect the modulator in parallel instead of series.

I tapped into this wire as I wanted to keep everything in the boot and not run cables up and down the length of the car. It is ignition switched and won't be difficult to repair if push comes to shove.

Neil

 

Right gotcha! I thought you'd gone after the loom behind the stereo with the old wire cutters Have you fitted the MP3 caddy in the boot then? How does that work??

 

Is there a gain control on the modulator ? Perhaps it's chucking out too strong a signal ?

 

Tif,

I bought an Archos Archos Jukebox Recorder. The intention is to put this in the centre compartment and listen to it via a FM station.

Steve,

yes it does have an adjuster, but this doesn't seem to make any difference to the radio reception.


Thanks for the suggestions guys. A colleague has just told me about a car hifi shop down the raod, so I'll pop in there lunchtime see if they've any ideas.

Neil

 

I've just got back from a local car hifi shop and they said that's how it's meant to work. Oh well.

It seems I need to install a switch to shut off the modulator. I was hoping to avoid that, but now I will have to switch on MP3 player, change the radio channel and switch on the modulator to listen to my jukebox. A bit long winded! I might have to consider a head upgrade in the not too distant future.

Neil

 

Bit slow getting to this thread (not that I can add anything of any value, of course), but I was surprised to read that there's an Aerial booster in our cars? Is that right??

Alex.

 

I would guess that the FM modulator is swamping the front end of the cars radio - the tuners in domestic stuff are not good enough to reject unwanted OOB signals.