High pitched "beep, beep, beep" when accelerating...

The Actia dash module had a recall but there have also been a few issues that are known to users. On mine it would occasionally show zero fuel, low oil pressure, etc, which would cause alarms to sound. There really wasn't a problem and the dash was easily reset by using the chassis battery disconnect switch to cut off power to the dash and allow it to reset itself.
You might try the reset procedure for the Actia dash and see if that corrects the issue.