Mattress

I have a ute that has intermittent smartlock issues. Sometimes its the fuel cutting off and others its starter motor wont cut in or both?? Ive seen a cpl of things forsale online. Just wondering how everyone else has fixed the issue. It only use to do it in the rain but now its happening in the dry aswell. 3 auto sparkies have looked but not been able to fix. Any help would be greatly appreciated