Radio aerial issue.

The other daughter rocked up this week from Scotland sans working radio....aux cable dosen't work either...no problem spare radio in garage. A few hours later we have a radio that works and picks up stations but no sound ...the graphic equaliser screen thingy is making like it is bopping to something...
Now when she bought the car the aerial was like most broken and bodged...tuned only to radio 1 , she retuned it and lost everything.
After fitting this replacement I attempted to do a better bodge and briefly found a local station that we could hear but when the antenna moved ....no sound again.
I also Sussed that if the antenna wasn't plugged in the radio didn't turn on , so the antenna is earth.
For now we don't have an aux cable to try , but why should a broken antenna stop the speakers from producing audio.

It's a cabrio ( but with hard top fitted.)

Cheers for input...it still has the original unbutchered loom , but has a wiring harness adapter , to allow the Pioneer item to join the Suzuki loom . If you know what I mean , Basically it a pre prepared loom that makes the power source and speakers connectors of the aftermarket radio join the single item from the vehicle.

I just copied the wiring diagrams from both radios which were the same colours .
I could not find a wiring diagram or list anywhere for the colours of a Jimny , hence a few hours to do the job.
Until I plugged in the new item ....( only then did we realise it wasn't the first radio being gash was the problem) did I realise the,issue must be earth related.....though why everything except the speakers works is a head scratch ...
If I knew what the Suzuki Jimny colour was for earth I can maybe sort it .
In older days car radios did earth through the antenna ....but it was either on or off,

Ah ah ...writing the reply above focused my attention on the aftermarket loom adapter , which seems is common and correct after a search on Internet ......however there seems to be a black wire with a ring connector on , which ours didn't Obviously the earth wire needs to join else where .......narrowing down to, do I need to join this to the radio , or the body of the car?
Am I correct in assuming because the loom dosen't have an earth from radio body , it's just using the first point it can find ...the antenna ?

Just a thought while searching this and other Suzuki forums history on this issue ...it was mentioned that after fitting , alarm or aftermarket central locking (which this one has) this issue appeared in other cases .....is this a red herring or can it alter the radio harness earth point of the cars loom ....seems a bit odd

If your new radio is standard ISO pin A8 should be the earth. So tracing this through should go to earth in the Suzuki loom.
Google ISO for pictures, may help.

Yep . Made a new piece up with ring on it , attatched to frame behind the ashtray frame ..ahah now radio on with out antenna coupled , much safer.....inserted USB key it recognises ....Unheilig playing, tells me the track number , No sound ...fiddle some wires ...Mein Stern plays for 10 seconds , then the sound is gone still playing but the system just dosen't want to share the tunes!
So it seems that it now beyond my limited time before she goes home as it needs an auto electrian to trace why the earth for the speakers seems have fell out with the rest of the loom..
On th plus side it is now safer than it was..
Ta.