Rebuilding Electrical from the "ground" up.

[ericpeltier]

So, I have a 33' 1972 Streamline that I'm doing the full monte on. As always, I'm thinking about next steps, and, I need to run some wires before putting all the aluminum back so I'm thinking about electricity.

Q1: For running, turn, brake lights etc, the system uses the chassis as a ground. I should stick with that, correct?

Q2: In disassembly of the trailer, it appears to me that the 12v system may have used the chassis as ground. Is that possible? My modern SOB trailer does not use chassis as ground for the 12v system, and I'm inclined to model that. Good route?

Q3: Does anyone have a detailed schematic of the wiring on a modern Airstream? I'm looking for a template to draw inspiration from.

Thanks in advance!

[dbj216]

Hello from Conifer! You are on your way with a HUGE project. You will experience most all of the human emotions during the time of this project. Smoking wires and a ruined converter may trigger one of the emotions you will experience.

Both my 66 Trade Wind and 86 Limited use the chassis as the ground for both 12v and 115v system. Maybe this is due to the fact that the Airstreams have all metal "bodies" on them.

Here is a photo of my 66 wiring diagram. It is likely nothing like your trailer. But you can use it to design your own wiring diagram. Generally your trailer runs on 12volts and uses 115 volts to charge the batteries, run the AC, and power some outlets for other amenities.

David

[HiJoeSilver]

As a good starting point rough sketch your trailer from above, (like top picture) then put in the living spaces and appliances. Look at where you'll live and think about where you'll want lights and outlets. Then think about where you might want some outlets that may be powered by an inverter like outlet for TV or plugging in laptop while boondocking.
If you're truly starting from scratch consider a progressive dynamics mighty mini for your ac/dc distribution panel.
Your air conditioner, microwave, and electric water heater, if installed should get individual circuits.

[HiJoeSilver]

One thing I like on that '66 wiring is that the outdoor outlet was at the very end of a circuit. In the 70s AS often put it in the middle of a circuit which often caused problems and lost power to the circuit downstream.
As an added note if you put a gfci in the first outlet of a circuit, all the downstream regular outlets get the same gfci protection. Just added safety.
Trailers get 120vac grounded to the frame for safety and electrical reasons. The 12v doesn't need to be if you don't use the shell for a return path at all, and home run all 12vdc circuits. Keep in mind many marker lights use the shell as a return path.

[SuzyHomemakr]

I was into boating before I got my Airstream, so I look to marine solutions as generally better than RV ones. A great author is Nigel Calder, who wrote a number of books on wiring boats. While often not directly transferable, you can get a lot of rock-solid basics and best practices.

When I rewired most of my trailer, I went with Blue Sea electrical parts. More expensive than your basic big box store, but worth it. I moved all ac electrical to over the sink, and built a custom cabinet that hinges down in the front to display everything. Very nice when troubleshooting!

Some things that I've done later, that would have been better done earlier:
Wired in surge/dip protector- I burned up some of my panel on a voltage dip
Added a larger inverter (Xantrex 1800w) to power a 110v fridge
Added a separate ac circuit that doesn't go through the inverter- it will only pass so much current before giving up
Wired in utility plugs outside for fans, TVs, lights, etc.
Wired for twin 30A plugs- living in Florida, I need two A/Cs

As part of my design, I made sure to put ac plugs inside of cabinets. You can always drill a hole through the wall to plug in, and you don't see a lot of messy wires everywhere. My TV (monitor) lives in its own cabinet, which has a plug for it and the Blu-Ray. Adding a cubby hole for personal electronics is great, and having its own power source inside means that you have a place to put your cell phone charger and other stuff out of sight.

Get a really good wire crimper! Solid wire is tough to get a tight crimp on with the cheapo crimpers. And write everything that you do down, make diagrams, and flag all of your wires, at both ends.

[Burnside Bob]

Originally Posted by ericpeltier

So, I have a 33' 1972 Streamline that I'm doing the full monte on. As always, I'm thinking about next steps, and, I need to run some wires before putting all the aluminum back so I'm thinking about electricity.

Q1: For running, turn, brake lights etc, the system uses the chassis as a ground. I should stick with that, correct?

Q2: In disassembly of the trailer, it appears to me that the 12v system may have used the chassis as ground. Is that possible? My modern SOB trailer does not use chassis as ground for the 12v system, and I'm inclined to model that. Good route?

Thanks in advance!

My 2009 AS Flying Cloud has 10 gauge ground wiring to all 12V electrical devices, whether powered thru the TV or the converter. Chassis grounding was not used on anything. The major structural components of the trailer--walls, end caps, chassis are individually grounded thru 10 gauge wire and bolts.

The thing to keep in mind is that more recent Airstreams, and presumably SOBs, have non-conducting material placed between the major structural components to reduce thermal transfer and to reduce shear forces on the rivets (the material appears to be a two sided adhesive high density foam tape between ribs and outer shell, and a black mastic with embedded fabric between endcaps and walls/ceiling). Even tho riveted there is no absolute ground path between structural elements, hence dedicated ground wiring and ground posts.

Yes, you can find 12V wiring diagrams that show chassis grounding, but they aren't for Airstreams. Best practice dictates a dedicated ground wire for each and every 12V device.

Suzyhomemakr has done a wonderful job well worth emulating, IMOP.

Best to you on your project!!

[SuzyHomemakr]

RE: Bob
What he said! (thanks for the compliment!) Whenever I've had flaky power problems, it's typically been because of a bad ground. I don't know if I'd run separate wires for all grounds, because then you're back to a single point of failure. Trying to tie all those wires together could be a problem, and then when you add a few more down the road, could turn into a mess. Also, electrical code (for houses) allows for a bare ground wire that is one size smaller than the two primary wires- but then, that's for 120 ac, which also needs its own set of grounds. Those run out of the trailer, and tie in to the 30A plug(s).

I tried to compensate for this by using lots of grounds (12V) tied into the frame. I also goo up the attachment point with dielectric grease. You've got a stainless steel screw, a copper wire and you're putting it into an aluminum frame. Definitely potential for corrosion!

Using terminal strips and bus bars is good for keeping things neat, and then grounding the negative side of the strip to the chassis can do a lot to solve this sort of problem.

[ericpeltier]

Thanks for all the help! I was into electronics as a kid, and got an engineering degree, but wiring up the 3 systems on a trailer makes me nervous. I sure wish SuzyHomemakr was my neighbor!

[SuzyHomemakr]

Originally Posted by ericpeltier

Thanks for all the help! I was into electronics as a kid, and got an engineering degree, but wiring up the 3 systems on a trailer makes me nervous. I sure wish SuzyHomemakr was my neighbor!

<blush>

Just take it a circuit at a time, and you should be fine!

[ericpeltier]

SuzyH
Do you have a link to DC paired wire that you like? Here's some I found on Amazon. Thoughts?

https://www.amazon.com/dp/B00MI5B2JI...I16PEO8JSNSJUN

Eric

[ericpeltier]

Now that I think about it, Jacketed is not needed. I just need lots of this:

https://www.superbrightleds.com/more...zqoaAkiD8P8HAQ

Agree or disagree?

[HiJoeSilver]

It'll probably work but without being able to see more specs I'd be hesitant, insulation material, temp rating. You can also use stranded THHN available by the foot and roll in many colors at big box hardware stores. Gives you a few more color choices to help identify different circuits.
You can also use marine tinned wire, nice but not wholly necessary.

[crestonrv]

I don't know what manufacturer is not bonding their dc system but needs bonded ! the entire body /frame of your streamline/silverstreak is ground . is ground and bond for a/c and dc . all rv's require both ac and dc chassis bond to meet iapmo code.

[HiJoeSilver]

Originally Posted by crestonrv

I don't know what manufacturer is not bonding their dc system but needs bonded ! the entire body /frame of your streamline/silverstreak is ground . is ground and bond for a/c and dc . all rv's require both ac and dc chassis bond to meet iapmo code.

Absolutely, even if you do all home run circuits, you still need to ground the system to the shell.
For the 12vdc side it's really easy, you just have to connect a negative 12vdc wire from the negative side of the fuse panel to the frame.

For the 120vac you connect a wire from the ground bar in the circuit breaker panel to the frame.

IMPORTANT IMPORTANT Unlike in a home circuit breaker panel, the neutral bus in the breaker panel DOES NOT DOES NOT get connected to the ground bus in an RV. IMPORTANT IMPORTANT

[dbj216]

Boy you are right on that one hihosilver. There have been some nasty shocks from the aluminum shell reported in these forums.

I'm no electrician. I always considered the neutral wire just as "hot" as the hot wire. The circuit wiring three lights in the ceiling is kinda like a "loop". The first light takes some power, the second light does to, as does the third light. Put your ammeter on either hot or neutral anywhere along this circuit, you are going to see current flow. You don't want the Airstream body carrying that current.

David

[SuzyHomemakr]

Originally Posted by ericpeltier

Now that I think about it, Jacketed is not needed. I just need lots of this:

https://www.superbrightleds.com/more...zqoaAkiD8P8HAQ

Agree or disagree?

I'd probably go up to 12 ga. And use lots of different colors of wire, to help with the inevitable troubleshooting at later dates. Keep on imagining getting into camp late on Friday, after a busy week, and something important doesn't work! Be a friend to your future self!

As you run your wires, maybe also put some good nylon string along the wires, and use grommets in your (oversized) holes. The string will help you to pull additional wires in the future, when your needs change.

[ericpeltier]

Good advice, Suzy!

I have already saved 90% of the little black grommets that came with my Streamline. And, I have concocted a plan to run chases under the subfloor so that I can run wires across the "hallway" when I want to add a circuit or add something I forgot.

[toastie]

Originally Posted by ericpeltier

So, I have a 33' 1972 Streamline that I'm doing the full monte on. As always, I'm thinking about next steps, and, I need to run some wires before putting all the aluminum back so I'm thinking about electricity.

Q1: For running, turn, brake lights etc, the system uses the chassis as a ground. I should stick with that, correct?

Q2: In disassembly of the trailer, it appears to me that the 12v system may have used the chassis as ground. Is that possible? My modern SOB trailer does not use chassis as ground for the 12v system, and I'm inclined to model that. Good route?

Q3: Does anyone have a detailed schematic of the wiring on a modern Airstream? I'm looking for a template to draw inspiration from.

Thanks in advance!

I ran all my ground wires to a single buss bar, then one wire from buss bar to tongue.

toastie

[toastie]

I found this very helpful...

toastie

[toastie]

Also this one....

toastie