Threaded Mode | Linear Mode

Aprilsailor

I have a similar situation where the wind direction on my ST60 does not seem accurate. I look up at masthead and see vane at 120 degrees relative toward portside, and read 60 degrees relative to port on display. I have performed the test referenced in attached and other notes on forum to check voltages from masthead transducer. I get the following (measured at display - no junction in cable between masthead and display):
Red to Shield = 8.02vDC
Blue to Shield = 5vDC (plus / minus 0.2 with dynamics)
Green to Shield = 2.8vDC (plus / minus 0.2 with dynamics)
Yellow to Shield = 3.6vDC (plus / minus 0.2 with dynamics)
Separate measurement of wind showed 10 knots at deck and a reading of 10-12 on the display, gave me confidence on the displayed wind speed. But direction was off by quite a bit.

The voltages for Blue and Green are within the range specified in the test note.... but are the voltages correct for the displayed 60 degrees or the masthead 120 degrees? If the measured voltages are simply within the range, does that imply that the masthead transducer is sending correct signal, and error must be cable/connections/display? Or can masthead send wrong voltage signal that is still within range?

Should I be spending a lot more time looking for corroded wire connections? We are talking saltwater Florida in this case.

Thank you for your guidance.