I recently moved the 7-conductor cable so it enters the body of my 1977 Scamp
over the right-side frame rail. I ran a 3/8" O.D. propane
line through the original 4-conductor wiring hole with a brass bulkhead fitting.
I searched for a better way of running the 7-conductor cable through the shell and found Ancor wire seals which are sold at marine supply stores. Ancor must be a division of the Marinco company. Here's a link to the Marinco web site:
Wire Seals | Marinco
I bought the 765004 from a local marine store because they didn't charge shipping for in-store pickup. My local West Marine store doesn't carry that size. It was about $15.
I was able to get the smaller 765000 size at West Marine which I will use for battery
wiring and brake wiring coming up through the floor.
There is not enough thread length on these to go through the plywood floor so I will mount them on an aluminum plate with clearance hole to clear the body of the seal. There is enough thread length to go through the fiberglass body.
Installing the wire seal for the 7-conductor cable was one of the quickest mods I've done. I used a hole saw and then opened it up a little with a round file for a tight fit.
It doesn't take much torque to seal and secure the cable plus is comes back apart very easily. No goopy sealant to deal with. It is waterproof to 300 ft. underwater.
I will try to post pictures tomorrow.