As stated in my other post, and the tech you are talking to must have the same idea that you have a grounding issue.
Yes there is a mounting point for the pump assembly to the plate it is mounted. There should be 2 bolts holding it to the plate it is mounted to. I posted a picture of my pump where I mounted it vertically to my uprights. You can see the bolt heads (not the nuts) that mount to the manifold section of the pump assembly. They are (2) 3/8-16 bolts. Make up a large ground wire and run it directly to the negative side of the battery then to the mounting lug of the pump assembly where the 3/8 bolts are. Make sure you scrape off the paint on the underside where the 3/8Ē bolt goes to, so it makes good contact.