New Stereo and steering wheel main beam flash mutes stereo

[Wenzil]

Hi All

I fitted a new stereo as the car kit was not compatible with new iPhone 7, it was a simple plug and play install, but since then when I flash someone or put the lights on main beam it mutes the stereo, any ideas

[Curdster]

A very very long shot but I seem to remember that the car side plug may have a lead linked to the speed output, so when the speed increases so does the volume. Could this be incorrectly wired or shorting somewhere post the car side plug or within it? I am not a sparky so just throwing out an idea.