Well this is bizarre. I have just come back to this thread to update my findings after 10 months, which is how long it took me to get around to climbing the mast and I see it has just been updated.
In our case I took the sender unit from the top of the mast yesterday, brought it home and tested it with the multimeter, only to find it tested fine. So then I went back to boat today and grabbed the display unit, brought it home and connected it directly to the sender expecting to find we had a wiring fault all along. But to my surprise, and concern, the fault remained, suggesting the problem was in the display unit.
I was about to give up and look for a replacement when it occurred to me to try one of the various calibration routines again, which I had already tried while on the boat. So I found the manual and tried the routines, no luck. Then I noticed the dealer install procedure which is a bit more involved, for a start it takes holding the two buttons down for 12 seconds, not four to get the device into the correct mode. I went through the options and noticed a reset to factory default option. What the heck, give it a go I thought. And hey presto, problem solved
. Full direction indication through 360 degrees, plus I noticed some interesting extra settings for response rate which I will play with when I am next out sailing.
So, for anyone searching on the fault who finds this thread, you should probably try the factory reset before climbing the mast, even when the calibration modes have all failed to fix the fault.
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