[rcflyers]

I have been having poor FM radio reception on my 2009 i30 so I removed the radio head unit to check the antenna connection was ok, it was.
I dropped down the back of the headlining in the boot so I could get to the antenna mounting. As well as the coaxial cable (that goes to the radio) there was another cable plugged into the antenna base.
Does anyone know what this does please?

I'm guessing it would be external powered antenna amplifier is it a twin or single core cable? if single it could be a pickup for phone signal 

[rcflyers]

Yes, possibly, it is a single core cable, I'm sure it was red/yellow.
Can anyone trace it on a wiring diagram please?

[tw2005]

Yes, possibly, it is a single core cable, I'm sure it was red/yellow.
Can anyone trace it on a wiring diagram please?

How about some imagery

[tw2005]

could it be yellow wire, orange trace? looks like there could be an amp built-in tp the antenna. , and that's the 12V supply, chassis provides the ground.

[tw2005]

definitely a power connector, says so in the workshop manual.

[tw2005]

[cruiserfied]

Bit late but yeah

[rcflyers]

Ok, thanks guys,
I checked the yellow/orange wire and it had 10 volts with the engine off.
Is there any way of testing that the amplifier is actually working?

[The Gonz]

Listen to radio with power to antenna applied and not applied.

[tw2005]

Ok, thanks guys,
I checked the yellow/orange wire and it had 10 volts with the engine off.
Is there any way of testing that the amplifier is actually working?

not without some specialised gear. What if you tuned into a weak AM station and then remove the power see if there is any change like no reception

[tw2005]

 

Listen to radio with power to antenna applied and not applied.

[rcflyers]

I tuned into a weak MW station and removed the wire at the antenna base and it immediately lost signal so I guess the antenna amp is working ok.

[yodm]

do you have a phone charger or anything plugged into the 12V outlet?
these things have a massive effect on radio reception quality.

[rcflyers]

Actually, yes, I do have a twin USB charger plugged in permanently.
I will try to unplug it and see, thanks for the tip.

[The Gonz]

Even the budget USB adapters just use a regulator, so I wouldn't be expecting reception problems (usually to do with frequencies, impedence and interference) unless it impacts power supply. If you come up empty, start looking at the integrity of the cabling and its insulation.