Replace exterior ground buss on camper
This is fixing something whose purpose I haven't a clue what its for. Looking underneath the campers wing, just in front of tie down plate, 3 solid and 1 strand 10AWG ground wires come out of camper. They are attached to lugs that are screwed to a thin piece of aluminum strip. The al strip was stapled to the campers WOOD paneling. When working on the camper few years ago noted the corrosion and I was going to move and clean up this Ground bar. But I got passed over, new trim from the project at the time covered part of the strip, so cleaning got moved to the round toit list.
Well Yesterday working on making our home made wobble stoppers more friendly I again noted this ground bar. Reached up and touched one of the wires thinking I should clean it (still not knowing its purpose) and 2 of the wires were loose. One wasn't tight in the lug, one the lug wasn't tight on strip. Hmmm. Went and got the multi meter and checked the ground bar and wires. 2 had continuity between lugs and strip, 2 didn't. One of the ones that had continuity was the one with loose lug to strip. As there is a star washer between lug and strip I'm pretty sure due to amount of corrosion my moving it caused to now make contact. So in essence 3 of the wires were not making contact to the strip.
As to the function of this I can only guess. I determined by guessing and testing that all this can do is connect the 4 leads to each other. Because the strip doesn't lead or connect to anything conductive or camper it isn't a chassis ground. Testing all the leads there IS conductivity between any of the wires and camper frame or any metal part, so grounding does occur elsewhere. Hence my conclusion is all this does is tie the grounds of the 4 circuits together. Or if one of the wires lost its ground it would carry thru this bar connecting it to another function ground and still have ground. Sort of a back up. That's really a wild donkey guess-but it cannot do anything else. . My biggest puzzlement is why this is mounted outside.
Regardless, though curious, it needs cleaning and fixing. I barely was able to remove. Screws on the lugs clamping the wires are steel & were severely rusted. Lil propane torch carefully heating then squirting with WD40 finally got them loose. Pulled the wires out. Unscrewed the lugs from strip. They went thru the strip into camper plywood so besides interconnecting lugs to aluminum strip also held it in place. Took the whole mess to shop. There is enough free movement in the solid wires I can clean, the stranded wire I can cut back to fresh.
The copper lugs are salvageable but would be a pain to clean. Threads still good as the screws once freed were mostly rust, so screws so didn't strip lugs. I could replace the screws and try to clean lugs. But I hadn't planned on this and don't want to do it. Making life simpler just buying new lugs. The aluminum strip unsure. I could just pick up a small ground buss. Mounting might be a problem. I do have some 1/4" x 1" aluminum flat bar. More mounting surface to camper. Mount the lugs to ba with 1/4-20 screws. Use separate screws to mount bar to camper. Getting on line the lugs come in a package of 5, so kinda sway me to make the buss bar. I can make larger cover old holes. Ill add the 5th lug as allowance. If I find this should also be grounded back to camper ( it wasn't) I can run another solid wire. If I were not so lazy Id pull the water heater for access and move this mess inside the camper. But I am and I'm not.
So off to the local ACE/ Miners hardware store.
I've already made new 'buss' bar. (4) 1/4-20 threaded holes for the ground wire lugs and a 5th one for extra lug.(4) #10 mounting holes. The arc is to sort of match existing wires. Less making them fit but better than the random as installed. New parts. Forgot to pick up 5th screw for additional lug. Though unless someone says this should be tied to chassis Ill just insert a set screw in unused hole to preserve threads.
. Old verses new
Removed most of the silicone. Always wonder why such a big blob of caulk. Originally drilled from top I assume and tore out vinyl covering- QC. Anyway I covered back side of threaded holes with small pieces of tape, ran the 1/4-20 screws in just enough to touch tape. This is to stop caulk from entering the threaded holes. Liberally applied caulk to back then installed the bar. Smooth out caulk...bedded. Let it set overnight. Anxious to finish but the lugs need to be pretty tight, don't want to disturb mounting.
Reshaping the solid wire fun. Due to bar is taller matching new mount holes bit of fineness to end up with wire in lugs without any tension. Wire brush then scotch bright clean solid wire, strand I recut to new clean wire. Applied dielectric water proof grease to all threaded and contact surfaces. Used star washer on both sides of lugs. Tightened all the screws. Small brush reapplied grease to inside of lug/wire screws hoping to stave off, well slow down, rust.
Just another shot-caulked it out. Tomorrow Ill mask off this area and paint. Use several light fog coats till I get coverage but not so wet paint seeps into connections-I just don't want to see. That and rust on exposed screws.
Need to check around see if this ground bar should be tied to frame or what the intent was/is. But done..though don't know what I fixed. Kinda odd fixing something have no idea what it is or for...
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