Yesterday, I installed the 5 amber Optronics oval lights on the eyebrow of our 2014 Sunstar.
First, the gotchas that I learned.
While the lights are the same physical size as the OEM lights, the mounting holes are a bit closer together. More about this later.
The larger issue is that they are not flat on the back. There is a 7/8" cylindrical projection in the middle, maybe 1/4" long, with the wires coming out of it.
After some thought (discarding the idea of fabbing up some sort of spacer) and measuring, I decided to do the right thing and cut 7/8" holes for mounting.
First I removed the old lights and carefully scraped away all of the old silicone used by the dealer techs, and the original sealant used by Winnebago. I made sure not to lose the wires falling back into the eyebrow
Since the existing holes had been somewhat worn by the dealer removing and replacing the OEM lights, and since the old wire hole was in the wrong place, I elected to plug them all with JB Quik 5 minute epoxy.
First, however, I measured and cut the holes with a 7/8" hole saw, and fished the wires from the original hole to the new hole. One wire was doubly cursed. The tech at the dealer we bought from did not correctly crimp the butt splice he used, so it pulled off the coach wire when I pulled it out of the hole. Then, the original Winnebago installer did the same thing, and when I was stripping the wire from the original light, that wire pulled out of the splice inside the eyebrow.
This was the left side light and wasn't that big of a deal, as I have already been in there from the inside cabinet before running antenna cables and replacing the radio antenna mount. So, I spliced a new longer wire inside the eyebrow and fished it out through the new hole.
Oh, yeah, another gotcha. The OEM lights were incandescent. Therefore the wires were both the same color. When I hooked up the new LED lights, I had to have the lights on to ensure correct polarity.
Back to hole patching. If you time the curing of the epoxy right, you can clean up any slop and trim the top of the patched hole flush with a sharp chisel or razor blade very easily.
Then, after splicing the new light on and making sure that it works, remove the lens, temporarily mount the light in the hole and mark and drill pilot holes for the mounting screws.
Caveat: It is tempting to use self drilling screws to mount these. Don't. There is a steel backing behind the 1/4" or so of fiberglass. If you use a self-drilling screw, it will drill out all of the fiberglass while the tip drills the sheetmetal. I predrilled 1/8" holes and used #8 Stainless Steel hex head sheet metal screws. You'd be surprised how many of the old light mounting holes had rust in them from poorly sealed screws.
Then, I pulled the light out of the hole, and laid down a layer of 1/8" butyl Tacky Tape to seal everything up, stuck the light back in, and installed the screws and lens, and then trimmed off the excess tape with a sharp knife.
This eliminates one mistake I have seen a lot. People install a light or a mounting bracket without any sealant between the surface of the motorhome roof or sidewall at the screw hole. Then, they seal over the top of the screw. However, water will still wick by capillary action under the mounted device and wick or seep in around the screw threads. Almost all of the shanks of the plated steel screws that held the satellite dish on this coach when we purchased it were half rusted away when I removed the dish because they weren't properly sealed.
The way I do it, the butyl tape seals the mating surfaces from wicking, and then seals the screw as it's driven in. On an exposed screw (not these lights) then I seal the screw head with a dollop of Dicor lap sealant. In some cases, I’ve been known to pull a little booger of tape off the roll and wrap it around the screw shank under the head to seal a screw.
Butyl tape also doesn’t harden or flow, and is fairly easy to remove later if needed, unlike silicon. (I really don’t like silicone for most applications…)
2014 Sunstar 31KE
1988 Suncruiser 31 RQ
1968 Travco 210