Rusted ground connection April 01, 2016, 11:03:01 pm Yahoo Message Number: 159660I have a less than a year old 2015 TK. While crawling around just looking at stuff, I noticed that a ground wire connection to the chassis had completely rusted away to the point where the ground wire was dangling free. The flat brass ground plate was secured to the frame with a sheet metal screw. I resecured it with a much better nut and bolt arrangement. I fired up the generator and plugged my portable power monitor/ surge protector into one of the inside 120v outlets and it said all was well. E=0.There are two ground wires in this location. One is simply a single bare copper wire perhaps #8. That one was also secured by a sheet metal screw but was not rusted. The one I fixed was a rather thick bundle, perhaps 3/8". It went straight up until it disappeared through the subfloor. Both of these wires are right under the battery box and near the generator.Question. What are the two wires? The single strand copper and the much thicker "bundle".Thanks Ed
Re: Rusted ground connection Reply #1 – April 02, 2016, 11:00:35 am Yahoo Message Number: 159662Ed, I'd suggest calling the factory--first because they will know what those wires are, and second because they need to know that these important ground connections came loose on a rig that's only a year old.Andy Baird
Re: Rusted ground connection Reply #2 – April 02, 2016, 11:18:51 am Yahoo Message Number: 159663I'd suggest calling the factory--first because they will know what those wires are, and second because they need to know that these important ground connections came loose on a rig that's only a year old.---- Definitely agree; unless the connections were damaged in some way, this should not happen at all, let alone on a new rig.Ed, if you have photos of the "before", could you post them? Thanks.Joan
Re: Rusted ground connection Reply #3 – April 02, 2016, 01:31:24 pm Yahoo Message Number: 159664No photos. The connector was simply a hex head sheet metal screw that went through the square, copper ground plate then through a hole in the frame that, I'm guessing, LD drilled for that purpose. The screw was so rusted, it simply snapped. Part was left in the hole and part in the ground plate. When I removed the remaining screw head from the copper plate, it simply fell out in my fingers. I'll give Vince a call on Monday. Ed
Re: Rusted ground connection Reply #4 – April 02, 2016, 01:40:12 pm Yahoo Message Number: 159665For TK owners. The grounds I'm talking about are almost behind the entry step in case you want to look. Ed
Re: Rusted ground connection Reply #5 – April 02, 2016, 01:40:56 pm Yahoo Message Number: 159666A related question. I'm satisfied the A/C system is grounded. How would a person verify that the D/C system is properly grounded? I.e. The 12v outlets.
Re: Rusted ground connection Reply #6 – April 02, 2016, 01:50:43 pm Yahoo Message Number: 159667If a zinc-coated sheet metal screw was used instead of a stainless steel screw, it may be that there was a galvanic reaction between the copper ground and the zinc-coated screw that cause the screw to fall apart. Obviously, the area described is subject to getting wet when driving in rain or snow, and water +zinc+copper are not a good combination. Joan
Re: Rusted ground connection Reply #7 – April 02, 2016, 03:57:18 pm Yahoo Message Number: 159668The setup you describe baffles me. Ground connections on a screw going through a copper plate into the steel frame? What were they trying to accomplish with the copper plate? I can't think of any reason why it would make things better electrically... and as Joan pointed out, there are good reasons not to put dissimilar metals in contact with each other. I'll be very interested to hear what Vince has to say about this.Andy Baird
Re: Rusted ground connection Reply #8 – April 02, 2016, 04:13:00 pm Yahoo Message Number: 159670I will call him, but I think I found out what I'm seeing.Electrical Grounding on Boats and RVsThe bottom drawing shows a typical RV ground setup. I' m guessing the bare solid copper wire is the solar panel ground and the one I call 'bundled' is for the house batteries.The copper plate is attached to stranded wires that, I'm guessing, come from the battery. Probably just as a way to keep the wires together as a ground.The camper is in the storage place or I'd take a picture.Ed
Re: Rusted ground connection Reply #9 – April 02, 2016, 04:25:49 pm Yahoo Message Number: 159672Does the LD manual have a wiring schematic that could give you a clue? My manual shows several wires that are grounded to the truck body. One is a black wire ground to the chassis from one of the negative house battery terminal. Look forward to seeing how this turns out. In the meantime, I'm going to crawl under our LD and see if I can find something similar.Ed & Margee - '09 MB Fort Worth
Re: Rusted ground connection Reply #10 – April 02, 2016, 04:54:21 pm Yahoo Message Number: 159676Ed, what part of the country do you live in. I'm curious as to why that screw rusted so quickly and if geography had anything to do with it.Chris
Re: Rusted ground connection Reply #11 – April 02, 2016, 05:03:28 pm Yahoo Message Number: 159677Galvanic corrosion.If all the ground wires are copper, and the are, and if all the Ford frame is steel, and it is, how could you connect the ground without two dissimilar metals touching? Since I'm redoing these connections, I'm open to ideas. Ed
Re: Rusted ground connection Reply #12 – April 02, 2016, 10:06:10 pm Yahoo Message Number: 159680Hello Chris. We live in Colorado. I suspect the winter "salt" that's used was a contributing factor to the rust. Going to redo everything with stainless.Ed
Re: Rusted ground connection Reply #13 – April 03, 2016, 04:11:37 pm Yahoo Message Number: 159686"I'm guessing the bare solid copper wire is the solar panel ground"A bare solid copper wire is almost certainly an AC safety ground. Judging by the location you mentioned, I'm guessing it may be from the generator. In any case, it's a very important wire."Does the LD manual have a wiring schematic that could give you a clue?"The wiring diagrams in the manual are generic ones, not specific to any particular model, and are of little practical value. I don't know whether LD has detailed schematics but doesn't bother to include them, or whether they just wire these things up according to Ancient Family Traditions."If all the ground wires are copper, and they are, and if all the Ford frame is steel, and it is, how could you connect the ground without two dissimilar metals touching?"Fair question. I would crimp on heavy-gauge tinned copper lugs, with adhesive-lined heat shrink tubing over them to prevent corrosion of the crimped connections, and then bolt those lugs to the frame. You'd still have tin touching steel, so there'd be some potential for galvanic corrosion, but overall you'd have a better chance of the connections staying in good shape.Andy Baird
Re: Rusted ground connection Reply #14 – April 03, 2016, 04:46:47 pm Yahoo Message Number: 159687I don't know whether LD has detailed schematics but doesn't bother to include them, or whether they just wire these things up according to Ancient Family Traditions. --- Pretty sure that it's the latter! ;-)Joan
Re: Rusted ground connection Reply #15 – April 04, 2016, 10:45:40 am Yahoo Message Number: 159697When I first opened my LD owners manual I was kind of taken back by the lack of a wiring diagram for the coach. Seems like something that should be there to inform the owner about an important subsystem.When these coaches are built, are the build guys supplied with a prebuilt wiring harness that is constructed per a factory wiring diagram or do they build the harness wire by wire from an instruction sheet? Who knows? In either case, detailed drawings specifying wire gauge, color, length and connection nodes must exist somewhere.I believe wiring diagrams for each model should have been developed and included with the customer information as this info has commonly been included or been available for download from other RV MFGs.This info would be invaluable if you had to trace out a broken wire in a wiring harness as I must do to find a broken sensor wire from the fresh water tank.Pete
Re: Rusted ground connection Reply #16 – April 04, 2016, 03:07:47 pm Yahoo Message Number: 159702I was at the factory a couple weeks ago and was shown wiring. Yup, it is "hand wired" so maybe no diagrams, though I bet it is fairly standard though I could see it changing over the years or as the workers changed.FYI, because I was asking about wiring, I was shown a coach that had insulation but no outside skins on yet. I noticed that Andy had a picture in the files that showed round holes with no insulation - show with a thermal camera I think. There were a couple holes in the side of the rig I saw that looked the same - I was guessing they were for electrical outlets/plumbing fixtures/etc. to go thru the wall, and there was no insulation in those holes.Another coach was being painted (visible from the showroom).Early on during our talk I was told let's look at that wiring now instead of later, I think when the coast was clear for me to go out there and not interrupt workers and/or get into areas that might be dangerous (e.g. walk thru a cloud of paint).There might have been more coaches being looked on but those were the two I saw other than the showroom ones (two in the showroom but it could fit another 1-2).Todd spend 2-3 hours answering all my questions (he got interrupted a lot the first half of my visit, probably from calls like some of you all make), but he made sure I got all the answers my questions as well as gave me information he thought I should have and didn't ask about (new inside colors coming out but they were not yet known).Jane
Rusted ground connection Reply #17 – April 09, 2016, 08:05:41 am Yahoo Message Number: 159805I also had to replace the ground fitting on our 1997/8 mid-bath. Here's a link to the Burndy KLU70 Scrlug that appears to be the match for the factory ground (and Ed's photo). As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: Rusted ground connection Reply #18 – April 15, 2016, 03:14:53 pm Yahoo Message Number: 159913I want to update something I said in message #159686 with regard to grounding.Back then, I wrote "I would crimp on heavy-gauge tinned copper lugs, with adhesive-lined heat shrink tubing over them to prevent corrosion of the crimped connections, and then bolt those lugs to the frame." That's good general advice for making connections to stranded wire, but in this case one of the two cables under discussion was a solid copper wire, and making a crimped connection to a solid wire is not a good idea! For example, NASA says this:"4.3.4 Crimping. Stranded wire shall be used for crimping (Requirement). Crimping of solid wire is prohibited. Crimping of solder tinned wire is prohibited."Other sources concur: crimping to a solid wire (or a stranded wire whose bare end has been made solid with solder) is a bad idea. I'm guessing that's because unlike with stranded wire, a crimp on a solid conductor (e.g., Romex) may only make contact in a couple of small spots. That can result in overheating. With stranded wire, the strands are squeezed into contact with the crimp's interior all the way around, resulting in a large contact area.(Truth is, solid wire is not recommended for mobile applications--think of all the reports we've seen of melted automatic transfer switch terminals, for example--but the practice is almost universal, so we're stuck with it.)In any case, I apologize for giving the impression that it was a good idea to crimp onto a solid ground wire. If that's what you have to work with, you probably can't do much better than what LD did: wrap the solid wire around a screw going into the frame... and pray that it doesn't come loose.Andy Baird
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