New head unit Road Angel RA-X722DAB help.

[RedAlexMc]

Hi all. First post. I have recently purchased a T5.1. The fitted head unit had problems with the volume control. I have purchased a Road Angel RA-X722DAB, connected. But only getting sound from the left speaker. The first pic is the rear of the new unit. 2nd the fitting in the van. 3rd is the new harness/quad lock I purchased. Any help very much appreciated.