I used spiral wrap along the length of the wires and then applied silicone where the wires enter the connector.
After a month or so of flying, the trim indicator on the EFIS failed and after much hassle turned out to be a bad connection from the wire harness to the plug, the wire just fell out of the terminal it was crimped to. I've never liked those plugs and their tiny crimped terminals. I replaced the plug with a d-sub 9-pin connector and it's been fine ever since
RV-14A #140158 flying