Troubleshooting the Retrosound Model One

The Retrosound Model One I have in my Jaguar had stopped working – symptoms were that the display was lit up in every possible place (i.e. like a digital watch showing 88:88).   This had happened before, and the cause turned out to be one of the 12v lines was not connected.   The Model 1 uses two 12v and a ground – one that is always live and one that comes on with the ignition.   In the Citroen, I have wired up a dash switch so I can listen to the radio without the ignition on as it does not have an ACC position, but I have not yet done this in the Jag as there is no obvious spot to do it.

To check the fuses in the Jag, the radio needs to be removed anyway – and it can be removed in a single ‘unit’.   In theory the fuse panel can swing out with the radio installed, but it does not on mine, nor did it in any of the cars I test drove when purchasing it.     I wired the radio up originally to make it easy to remove, with three quick disconnects.

One of these was a bit loose, so I put on a new end.   This was not the problem.   Next was to re-connect the battery and use a multimeter to test the power lines with ignition on and off.

Using a multimeter showed power where it should be – always on for the yellow wire, with ignition for the red and black for ground.   The inline fuses for both wires were also ok.   Given the whole unit can be removed from the car, it is easy to bench test.

A quick bench test showed that the radio was working correctly, so I had to head back to the car to check the wires again.    After quite a lot of trial and error I found what looks like the problem.   The wires all work correctly with the fuse panel open, but not when it is closed.   Two changes seemed to help.   Firstly making sure the yellow wire had enough slack so it was not under pressure when closed, and secondly taping up a wire that had broken off the interior light fitting.    No time to re-install the radio today, but it looks like the problem was that simple.     I also now have a simple bench tester I ‘made’ out of an old switch I had, as well as a cigarette lighter adapter.