EV1 FAILING

[ifmdlvey]

Hello
I have 2xi70, p70, EV1, ACU and a E120classic.
The system has worked well for 2 seasons but recently my course computer has been playing up.
The compass offset is all over the place.
I align compass to gps audit holds for a while but appears to wander off after any heading change.
I have checked and there is no no new pieces of metal anywhere near the EV 1 location.
The system switches from mag to true all by itself.
To me its like i am getting erratic deviation or variation inputs for no reason, is there a solution or do i need the EV1 replaced?

As an aside, i installed a Ray70 last winter, i get AIS contacts on my I70 but nothing on my E120, the symbol for AIS has a red line through it - do i have a compatibility problem?

thank you
Ian