[danny_mcgee]

I installed a Kenwood stereo and everything works except AM/FM. Originally, I didn't connect the power antenna cable from the stereo to the remote antenna connection on the harness. After I made the connection, everything works great when the key is in ACC. Once I change the key to ON or START I lose the signal or it is weak. Any suggestions why this is?

[Phil №❶]

One can only assume that power is unavailable when the signal drops out. Are you sure you have made the connection to the correct pin. Use a multi meter to verify power is available in all key modes.

[marcopolo]

Danny are you sure, that you've got powered antenna ? In European i30 (>2009) there is passive antenna. I also installed aftermarket multimedia station and only needed to change the antenna pole for longer (now it is about 60 cm long). Antenna works without powering, it hasn't any amplifier. Reception is good.

Maybe adding voltage to non-powered antenna cause interferences ?

It is high possible that Phil is right, so try him advise.

Always you can change whole antenna installation for aftermaket passive (or amplified) antenna with long mast. And I'm sure that it will be good option.

[danny_mcgee]

Ya, I will have to check the voltages at the different key modes. It's just weird that when the key is at ACC, AM and FM come in perfectly after I connected the antenna power.

[Phil №❶]

That proves that electronically, there is no fault with the radio or aerial, it appears to be just the supply of power to the aerial.