2013 Chevy Express Thomas Minotour Build - 4 Window, 6.6L Duramax

[njl1031]

Hey folks!

Going to be starting this build in a few weeks and plan to document my progress here. I've started gutting it, but dropped it at my mechanics for a few weeks to get it converted to 4x4. This will be the biggest cost of this build, probably more than the rest of the build, and something I've been so excited about and saving for for a while!

The bus is a 2013 Chevy Express 3500 with a 6.6L Duramax Diesel engine, a 6L90 (6-speed) transmission, about 95,000 miles on it, and a Thomas Minotour body. I stalked the interenet for several months before jumping for this one for $7000. I really wanted a diesel with a beefier transmission, and the low miles and low rust convinced me to buying a newer once, which I immediately payed for with some emissions issues, but so be it.

The 4x4 conversion is being done by a mechanic I know back in Colorado who runs a 1-man shop and loves doing his own custom 4x4 projects. A conversion like this could be done by a DIY-er but without a garage and a lift it would be a huge PITA. A lot of parts are coming rebuilt/salvaged, sourced either by my mechanic, or by Timberline Supply in CO. Those are the guys that put together the conversion "kit". They custom fab a few mounting brackets that are needed, and compile a list of other parts needed for your to source yourself, or get through them. Parts for this conversion are $5k-$10k and it's 35-55 hours of labor if I remember correct (so another $5k+).

The inside is a mess right now. I took out the benches (me pictured under the bus, frustrated that my friends up top are posing for photos instead of hold a wrench to the bolts). I've removed some of the interior trim and walls/ceiling panels.

Once I get it back from my mechanic I'll be doing a roof raise and window delete, cheap shitty paint job, and then racing the winter weather to get a basic interior to live in while replenishing my bank account for a more gradual full interior build.

I'll post some floor plan, electrical, and plumbing concepts later, would appreciate any critique of them.

Thanks for getting this far, I'm super excited to share this build process!

 

[baadpuppy]

Hey folks!

The 4x4 conversion is being done by a mechanic I know back in Colorado who runs a 1-man shop and loves doing his own custom 4x4 projects.

Ooooh, a 4x4 conversion. I am envious of you. I look forward to seeing what you do with it! Seems like a decent starting platform to me.

Jim

 

[AlphaHare]

I'll be interested to see how this turns out! Where do you ski?

This is probably too much for me. But I am thinking a Weldtec lift and spring kit, and a rear locker. That's probably as wild as I want to go.

 

[nikitis]

Just one suggestion.

If you are going to be living it out in the Winter, after the roof raise I'd prioritize the insulation next cause you're gonna freeze in it otherwise.

 

[njl1031]

Well I realized that my photos didn't add to my post, I'm still learning how this works. Let's see if it works this time.


Here's the bus pre 4x4 conversion, and me undeneath working on bench removal while my friends inside are clearly not holding a wrench to the bolt heads








And here's the interior that we're working with, total mess.

 

[njl1031]

I'll be interested to see how this turns out! Where do you ski?

This is probably too much for me. But I am thinking a Weldtec lift and spring kit, and a rear locker. That's probably as wild as I want to go.

I've been up in Breckenridge the last two winters, but I plan to go elsewhere this winter, maybe Taos. I was living in my converted Chevy Express van in Breck, but it's just too van unfriendly for me there.


I ran a limited slip on the old van, and plan to run it on this bus as well. The Detroit TrueTrac. It worked amazingly well in snow and mud, and decently in sand too depending on how deep it was because of the heavy vehicle. Lots of research convinced me to go with that over a full locker because of on road handling issues.

 

[njl1031]

Just one suggestion.

If you are going to be living it out in the Winter, after the roof raise I'd prioritize the insulation next cause you're gonna freeze in it otherwise.

Yes of course! That's a given in building a simple interior for now. I'll be adding 3" of XPS board on the floor and ceiling, and 2"-3" on the walls, and adding plywood sheathing all over. I'll have my floorplan decided so I'll lay the wiring already as well so I can hook up my diesel heater and a basic water system for the time being.

 

[BMWNJ]

Ohh a 4x4 Chevy bus! now there's something you dont see too often! I'm looking forward to following along.

 

[AlphaHare]

I've been up in Breckenridge the last two winters, but I plan to go elsewhere this winter, maybe Taos. I was living in my converted Chevy Express van in Breck, but it's just too van unfriendly for me there.

Thanks for the locker advice!

We did Taos three years ago - rented a place in town for two weeks. Awesome town, pretty chill in the winter, and a bazillion places to put a van, including a van/rv specific lot at the ski area. Big hill - great tree skiing. Take a loop around to the east as well on 64 and 38. Red River looks like fun, but haven't skied there (yet.) Go west over the gorge and you have all the room in the world....

 

[njl1031]

electric diagram first draft

No build updates yet. Mechanic keeps pushing my pick up date week by week. A part got delayed, then a wrong part was sent, then a part didn't fit quite right and needed adjustment. Latest was that everything in the conversion is in, just the fuel tank had to be moved a little so the fuel lines have to be altered to accommodate. Then it should be ready and my work begins.


In the mean time, I've had unlimited amounts of time to research parts and design my build. I'll post some photos of my bare bones sketchup design later, but for now, here's where I am with my electric diagram. Thoughts?






I know it's a little extra perhaps, I just figured I'll go all out since this will be my full time year round home for at least 5 years.


This isn't a final draft by any means, but I'm looking for feedback on anything glaring or minor that I missed or could change. In particular, I'm coming up with many conflicting opinions online about grounding, and I'm trying to decide what the best distribution system to my loads is.



Grounding Folks over at Battleborn said that in a on-wheels application I shouldn't ground the MPPT or Inverter/Charger chassis, only in marine, residential, and industrial settings would they be grounded. The Victron manuals are unclear because their use of the term "off-grid" is vague. Online I see RV/van/skoolie folks grounding them... Thoughts? Do y'all ground your PV array frames to the roof of the bus?


Distribution My first instinct was to decentralize my DC fuse boxes and set several of them in different zones to decrease cable runs from all the various lights, outlets, and other devices. I was thinking of the added resistance of longer runs, but also the messiness of having dozens or 12/2 wires winding their way around my bus back to a central point, instead, I'd just have 5 larger gauge wires going off from a central point feeding fuse boxes in zones. Additionally, if I ever want to add more wires, I don't have to rip apart all of my walls, I can just remove walls panels in one zone to access the local fuse box. In the case of this design, I currently have that central point being a bus bar with fuses attached, though I think a DC breaker box would be cleaner and maybe make more sense.


Alternatively, and as suggested by the folks at Battleborn I was talking to, I could have the whole thing centrazilzed. One fuse box for all the DC loads, located in my main electric compartment alongside the AC breaker box. This make diagnosing issues simpler and uses less connection points that are points of increased resistance and could come lose, but as mentioned above, this means every single device would have wires running all around my rig back to that point.

 

[AlphaHare]

This is a great read from Victron.

https://www.victronenergy.com/uploa...imited_book/43562-Wiring_Unlimited-pdf-en.pdf

There is a great section on grounding with good illustrative pictures.

My understanding (but I'm not an authority):

The MPPT is non isolating. The MPPT neg DC input is already attached internally to the MPPT neg output. If the DC negative system is grounded to the bus chassis (the big bus bar), so is the array.

The chassis of the Multiplus and MPPT should be grounded.

The Multiplus AC ground SHOULD NOT BE GROUNDED. The AC system 'floats' which is safer in a van where there is no true 'earth' ground.

As with anything electrical, seek professional advice when required. No shame in not being electrocuted.

 

[Buseatinglunatic]

Have you figured out insurance yet? I have the same bus and completed my build, freaking amazing build I just can’t get affordable insurance.

 

[AlphaHare]

Have you figured out insurance yet? I have the same bus and completed my build, freaking amazing build I just can’t get affordable insurance.

I can only tell you my experience in Massachusetts. That said, it should work anywhere.

Look up your VIN number. It should be an incomplete chassis, meaning Chevy sold a 3500 cut-away chassis to Thomas.

As such, it's technically a van. My insurance company (Liberty Mutual) actually worked this out with me, and the same at the Registry of Motor Vehicles when I applied for a new title and registration.

It's only a 'school bus' if you say it is. The VIN is an incomplete van and I told my insurance company i was using it for utility and work. Which I am until I start camping in it....

The only problem with this scenario is when you have finished your build out and want to get coverage for the full value of your RV/Skoolie. At that point, I'm going to look at RV registration and insurance. And I'll have the best documentation I can make of the rebuild to NFPA 1192 and NFPA 70.551.

 

[AlphaHare]

Another comment on the electrical system - since you asked - I would rethink the start batteries.

Look at the Victron schematics for the 3000VA Multiplus.

I would not want my start batteries supplying my house in any way. (If you keep it as shown, best to add an isolation switch IMO.)

 

[Brian35]

Any update on the build? I have a van and kind of want a 4wd bus now..