hey everyone! I've finally got the entire outside built and sealed from weather on my 20 foot 1979 ford class C! I've got the new clearance lights/tail lights and 4x fantastic fan vents on there, ready to be wired. I'm going to wire those and all my 12v wiring needs(sockets, lights, etc). I can't put the actual sockets or figures yet because there are no walls, but I can run the wiring before the spray foam guy comes. the motorhome at the moment, is a tin box with wood sticks framing it on the inside. I have full access to wire where I need.I know which wires go where for the most part, but what I don't know what to do is how to ground my 12v stuff. the fantastic fans, lights, sockets etc. when I was a kid, we had a Cortez and the generator was grounded to the outside panels stupidly, so if you touched ANY metal on the outside of the motorhome while the generator was running, you got a shock. this tells me not to ground to the thin outer panels, and that I might have to run grounding wire for everything. is that the case?which of these things need grounding, and where can I ground them to?clearance lightstail lights/blinkers/running(one fixture)fantastic fans12v socketslong story short, I'm moving into this in 3-4 weeks. it'll be pretty bare bones with wiring and insulation, basic appliances(Coleman stove+compost toielt+cooler), and my bed. in march when the ground isn't snow covered, I can finish the build but for a few months, this is what I have. so now I wire it and insulate it.

Everything 12v must be grounded. Ground to the frame at the nearest practical point.

oh boy going ion amazon to see what I need is a bit daunting. all the lights are mounted, and I have a solder gun/solder but I don't think I have flux. iu can go get some, but it seems like some solder has it built in(for lack of better term). type of solder thicknesstype of shrink wrap/sizeshrink wrap tubing for some reason is not sold/advertised in appropriate wire gauge sizes, but rather are listed in MM sizes. I don't know how 14g translates to mm or why they do that but its very confusing. I have no idea what to get, should I go for the "rosin infused" wiring? if so, what ratio? what size shrink tubing? when I run positive/ground from one to the next, I just solder them together and shrink wrap right? like daisy chaining for clearance lights? thank you soooo much!

Don't see why one would need to shrink wrap/insulate the 2 volt ground.

its code to make them waterproof, for the lights anyway. please, type of tubing for 14-16g? any advice for solder?

If I were you , I would be satisfied with crimp fittings and wire nuts. Solder and shrink wrap is great but time consuming. To answer your question about the size of shrink wrap, I probably have eight or ten different sizes and as many colors. All of mine are in inches and not mm so here is the solution. Buy a variety pack from HFT and use the sizes closest to the wires being insulated. I used to use a match to heat but now I use a heat gun from HFT. I have not seen plain solder for a long time and I would just buy a solder that contains acid free flux, it's not rocket science. solder size is dependent on the gun or iron you're using. I have been using Kester, "44" rosin core solder that is .050 diameter for most things. I don't solder bigger stuff like 14 or 12 gauge, for that I use crimp fittings or insulated wire nuts.For connecting the fixture wires to the house wires I use mostly wirenuts and have been since we bought our first rig.I assume you are not going to insulate your interior walls and I would suggest you pull a pair of #16 or even 14 wires to each wall for future use. The wires can be coiled in a box or just left coiled in the wall. You're not going to be able to install them inside the exterior walls and ceiling once the insulation is in.When we built our home, I photographed the entire electrical and plumbing systems when the rough in work was done. Before I drill a hole in a wall I consult my photos to make sure I won't be hitting either a wire or a pipe. I also chose to have flex and pulled wire installed, I have pulled extra wires in several locals including, directly over the desk where my computer is. The ceiling fixture is behind me and was great for a bedroom but lacking for use as an office.Good luck and don't over think your project, K.I.S.S.

clearance lights/fantastic fan grounding | Good Sam Community

15 Replies

Mako_Kupo
Explorer
Dec 13, 2017
so what I've done is run all of my circuits through the open walls, I have black and white running right by all clearance lights, all wiring for tail lights/license plate/reverse light/etc ready to connect, and all of my 120v and 12v circuits run. I won't be connecting any of the 110 to fixtures or even a converter yet(they sent me the wrong one, sent it back and never ordered the new one). I have spray foam being done this weekend, so the goal was to have all the wires in *roughly* the correct places before the foam goes in. I left about 1-2 feet on each end of every circuit for play/safety room. 4 fantastic vents(one is temporary so I'm using the light circuit for the fan until march, then ill switch it to a light fixture and put the AC in.

I didn't think it was a good idea to ground to outside panels, since I got electrocuted a kid that way. my old cortex was grounded to the outside(generator) and if you touched any metal at all while it was running, you got a shock. that won't happen with clearance lights? I know the voltage is way lower but I still don't want to have to avoid touching the outside of the camper ever.

I ordered a few different kinds of solder(were like 2-5$ each, not too bad). I got lead free, 60/40, and petrol based acid. I have friends ill give the extra to, so it works out. you guys say no rv companies solder but all of my 12v connections were soldered from the original converter, but the 110 were wire nutted and had very modern Romex so whatever I pulled out for 110v was not original, meaning I don't know how they did it originally.

I'm forced to move into this thing on January 1st, so I don't mind painting pray foam and leaving it for a few months open, as long as its warm and I have SOME power. luckily I already have my compost toilet, which uses very little 12v power so with that, a Coleman stove, a cooler, and my furnace the next few months won't be too too bad and I can finish the inside in march-april.

next, I'm going solar. I do not have a converter so most of my circuits are useless for now, but I do need to order this weekend, a small solar set to get me by for a bit. this is what I'm getting, I believe it is all compatible
BATTERY. https://www.amazon.com/LiFePO4-volt-Deep-Cycle-Battery/dp/B06XX197GJ/ref=sr_1_1?ie=UTF8&qid=1513173561&sr=8-1&keywords=battleborn+lithium

mppt controller https://www.amazon.com/gp/product/B01GMUPGZA/ref=ox_sc_act_title_2?smid=A17GQCX3W4R1TW&psc=1

2 of these panels. https://www.amazon.com/gp/product/B009Z6CW7O/ref=ox_sc_act_title_3?smid=ATVPDKIKX0DER&psc=1

inverter. https://www.amazon.com/gp/product/B06XPRJ1HB/ref=ox_sc_act_title_1?smid=A2TN19FHI2Z5KL&psc=1

I will be running from this power alone for a few months. doable yes, could be better but the controller will allow me to upgrade to what ill need in the end so the only thing ill ever need to add to this is more batteries/panels, the controller will last a few years for what I need. no matter where I look though, I can't find out if it will charge 14.4-14.6 volts which that battery needs.
westend
Explorer
Dec 13, 2017
Mex got it right on the supplies. I'd strongly suggest to make your 12V wiring, a two-wire schedule, one for (+) phase and one for (-) phase. Connect 12V ground onto the frame after shining and preparing the surface. Use locking washers and suitable connectors/fasteners. The reason to use two wires is that finding a failed ground point after the walls have been sprayed and paneling is up will be a hair-pulling event.
MEXICOWANDERER
Explorer
Dec 12, 2017
four millimeter heat shrink tubing is fine for 14 gauge. If you select 4:1 tubing it means it really shrinks a wide size of wires.

I've used paste flux like sold in Home Dept for five decades on everything from 22 gauge to wire fatter than your thumb. It works faster and more thorough than electronics flux with is fine for transistors. You'll find this flux in a small jar in the plumbing section.

But for solder you absolutely must be picky. Either 60/40 grade or 63/37 grade. Electronics grade solder -- doesn't matter which flux is in inside it. Beware of lead FREE solder -- it melts about at the same temperature as cast-iron (a joke). Way too hot and hard to use.

If you are going to "ground" the clearance lights against the aluminum sheet metal, you will need # 6 threaded screws, nuts, and lock washers. Shine the sheet metal after you drill the hole. After bolting on the "ground" wire, smear a gob of grease over the bolt head and wire terminal. This is not optional -- you have got to seal this joint. The connection goes UNDER the lamp so as to hide it.

You don't need to defend the way you've elected to do this.

The best heat shrink values are found on eBay. Remember FOUR MILLIMETER.

https://www.ebay.com/itm/4mm-Adhesive-Lined-4-1-Black-Waterproof-Heat-Shrink-Tubing-5M-Tube-Sleeve/151788167203?epid=1347112292&hash=item235747a023:g:IvgAAOSwJcZWcQ7Y
beemerphile1
Explorer
Dec 12, 2017
I don't know what code you are referring to, RVs are built to RVIA standards and no RV manufacturer solders connections. The 12vdc connections use either crimp connectors or wire nuts.

Do be sure that all 120vac connections are inside boxes and are not sealed up inside a wall.
Mako_Kupo
Explorer
Dec 11, 2017
yes, thank you I have 1/2" split black conduit, same as the mechanic used.
DrewE
Explorer II
Dec 11, 2017
120 volt wiring in wet locations must be installed properly to code and suitably rated for wet locations. I suspect that is what the mechanic was referring to. 12 volt wiring does not have the same code requirements; if it did, every car on the road (or at least all that I have seen) would be illegal. The 12 volt factory wiring on my motorhome is not waterproof at all where it is exposed; it's mostly ring terminals and bolts or screws for the ground connections.
1995brave
Nomad
Dec 11, 2017
Since you are having the inside spray foamed you might want to put all the wiring into flexible tubing a little larger than the cable diameter (1/2 inch split loom would be good) in case you need to run more wire or replace a bad one.
Mako_Kupo
Explorer
Dec 11, 2017
the mechanic that came and clean installed my wiring from the fuse box back told me it needed to be shrink wrapped if its on the outside of the vapor barrier, which it is. no I'm not a mechanic or an electrician, the information I go by is what I'm told by the professionals that come to do work for me. I rely on that, sorry if I don't automatically jump on the first answer when I'm given several solutions at once from multiple sources. on top of that, I've been working on this 12-14 hours/day for almost 3 months and am entirely exhausted. I've had to reverse SO MUCH work that people did wrong, or I did wrong because I listened to the first thing someone told me.
D_E_Bishop
Explorer
Dec 11, 2017
Mako Kupo, it is obvious that you are neither an wlwctrician nor an auto mechanic and you have asked us for help, how much more definitive do you want us to be? I quoted name, make and serial number for you and you when questioned as to why you needed to do something said and I Quote, "It's code to make them waterproof...". So I have a question for you, "WHAT CODE", and what section of that code.

It seems logical to me that your batteries are grounded to the chassis and that any circuit using battery power can use a chassis ground and I do not remember any chassis ground on a motor vehicle being waterproofed.

Of course I may not be familiar with all codes but I've been in the trade since I was fourteen and working on cars since my Dad taught me to overhaul an engine when I was ten and I have never heard that.

I'm not trying to be obnoxious but some of use on here are very up on how and why and even have college degrees in some of the related sciences. We're just trying to help you.
Mako_Kupo
Explorer
Dec 11, 2017
I wish it could be what I was satisfied with, but thats besides the point since code says they need to be soldered. I'm wiring the entire camper before putting in spray foam, including 110 and 12v. I can't use crimps, they have to be soldered. ill have several extra circuits run as well, I have a new AC I'm not putting on until the summer but I'm definitely running the wiring for it.

they definitely need to be soldered though, so I do still need to know what kind to get. thanks for the info!