ST50 + wind display

[CaptWil]

Hi

I recently refurbished the mast transducer for my ST50+ wind instrument; the original display was not working when I bought the boat
I bought a used spare replacement head and the damn thing also does not work
I checked all the wiring and voltage( using a 9V power source) reading on the cables from the mast head transducer as per Raymarine instructions and it works fine
But when connecting the display head normally on the network, my voltage from shield and positive is only 4.5V? thought it was supposed to send 8V to the mast?
I get that voltage from both original head and replacement unit
The wind indicator goes to 120 degrees Port, wind speed is working, displaying on unit and my Tri Data as well; then the wind indicator goes back to center Zero, and the wind speed just stops.. Switch the Raymarine network off, wait 5mn and switch back on, the wind instrument carries on as before and stops again.... Also noticed the back of the display Tru/App is very hot
Ideas?
Thanks
Will

[senormechanico]

Disconnect the mast transducer and check back of display for "hot".
Does it still get hot? If it does, it's an internal problem in the display.
If not, check the wiring for a short in the mast or masthead transducer itself.

[CaptWil]

Thank u Senormechanico

Yes it looks like the mast transducer is the culprit after all

No sense spending more good money fixing this old stuff; I was trying not to demast for my new windsonic/N2k upgrade but have to go that way now since I bought all the equipment a few months back

U say "demast why" m sure. Well the access for the new thicker wiring will simply not cooperate size wize so have to demast, drill the plate under the mast step etc... lots of joy

Cheers
Will