Why an Ambulance?
This rig started as a 1990 Ford E-350 ambulance.
I turned it into a fully off-grid, four-season tiny house on wheels—and then lived in it for a year and a half through one of the nastiest Missouri/Kansas winters on record. No hookups. No generator. No propane. No gimmicks.
If you’ve ever wondered whether an ambulance is a solid foundation for a tiny home, or how far you can push a 30+ year-old platform into modern off-grid territory, this is the full tour: systems, layout, heat, power, water, and why I’d absolutely do an ambulance again.
Why an Ambulance?
Quick answer: they’re built to protect people, not luggage.
All-aluminum box construction
Reinforced framing designed for crash survival
Tons of exterior compartments
Factory wiring and access for upgrades
Short enough to park at a grocery store, stout enough to live out of
Compared to a lot of RVs, an ambulance box is overbuilt in the best way. When you’re trusting one vehicle to be your house, office, and winter bunker—that matters.
Chassis & Driving Setup
This rig started life as a 1990 Ford Econoline E-350 with a 7.3L IDI (International) diesel. Naturally aspirated, simple, serviceable, not fast—but dependable.
Up front:
Clean, functional cab with pass-through to the living space
Outdated ambulance switch-gear removed
Two custom-wired auxiliary switches ready for:
Future roof light bar
Spare circuit
Retained and wired-up pivotal search light (genuinely useful)
Upgraded head unit for navigation, music, and streaming
LED headlight upgrade for modern, safe nighttime visibility
Block heater ready for cold starts.
It’s a work truck, not a toy. But tuned, cleaned up, and sorted—it’s road trip ready. I’ve run it on long hauls (including Florida and back) without drama.
Exterior: Built for Real Use, Not Just Instagram
The entire box is coated in Durabak 18, an industrial coating used by the Navy. It’s:
Tough
UV-resistant
Easy to wash
Not precious
Perfect for branches, gravel, and not worrying about babying your paint.
Key exterior details:
New LED tail lights for low-draw, high-visibility braking and signals
Heavy-duty welded rear tow bar:
Properly tied into the frame
Wired for trailer plug, trailer brakes, and 12V service
Realistically: great for bikes, light moto, small utility trailer
Fully loaded, the rig is ~10,500 lbs — so don’t tow a house with it
Upgraded scene lights:
Original ambulance perimeter floods converted to high-intensity LEDs
One switch and your whole campsite, trail, or sketchy parking spot lights up
Awesome for night work, security, repairs, or just “midnight daylight”
Side-mounted deck hatch / vent over the shower
Shore power inlet (rarely needed, but available)
External camera mount points for Arlo or similar systems
This thing is not stealth. It’s honest. It looks like what it is: a capable utility rig turned tiny home.
Suspension & Handling
Before I added air bags to the rear!
Stock ambulances ride soft when empty and saggy when loaded. This one’s built to carry weight.
Bluetooth airbag suspension system on the rear:
Independently adjustable left/right
Level the rig at camp without blocks
Compensate for load, water, or gear
Improve ride and stance when fully loaded
Dial it in from your phone, get your headlights out of the trees, and sleep on a level bed.
Off-Grid Philosophy: No Propane, No Generator
The entire build is centered around three core ideas:
Live off diesel + solar
Be truly four-season capable
Minimize compromise
If you can find:
Diesel
Water
Sunshine (or at least not endless darkness)
…you can live in this rig comfortably for a long time.
Water System: Secure, Simple, Winter-Ready
Right inside the main door:
55-gallon fresh water tank, mounted inside the insulated space
Interior fill port:
No external cap for people to mess with
Just crack the door, hook up a hose, and fill
Integrated sight tube to monitor level
Why interior fill? Control and security. Nobody touches your drinking water but you.
Gray water:
Dedicated gray tank for sink/shower
Designed to be used with biodegradable soaps
When conditions allow, minimal-impact drain use is possible
No black tank:
Composting toilet inside the wet bath
No sewage dumps, no black tank freeze risk
Interior Layout: Compact but Legit Livable
When you step in:
Wall-mounted broom & fire extinguisher
Catch-all shelf + overhead cubby for keys, hats, gloves, small gear
Warm-toned, moisture-resistant flooring
Beautiful butcher block countertop (≈7 ft long, 1.5” thick)
Under-cabinet lighting switch located right at the entry
This is a small rig, but the layout is intentional—nothing feels like an afterthought.
Kitchen & Utility Core
Slide-out fridge/freezer on 500 lb locking drawer slides:
Tucks away while driving
Locks in place so it doesn’t launch on corners
Microwave powered off the house system
All 120V and 12V systems run from:
Solar + Tesla modules
No generator required
Hot & cold water at the sink with on-board filtration
Everything up front is fed from the house system, not the alternator batteries.
Lighting & Ceiling
Full-length dimmable LED puck lighting integrated into a gorgeous cedar ceiling
Simple touch control:
Tap = on/off
Press & hold = dim/brighten
Exposed aluminum structural brackets:
Aesthetic
Honest
Reminder this thing is built like a rescue rig, not a toy camper
Bath & Composting Toilet
Compact, functional, and designed for real use:
2 ft x 2 ft shower footprint
Composting toilet
Venting deck hatch for moisture & fresh air
Low-flow handheld shower head
Single mixing valve outside the shower:
Set your perfect temp once
Shower line feeds that blend
No fiddling with hot/cold knobs each time
Easy to readjust if multiple people use it
It’s a tiny shower, but at 6’1”, I fit. If you aren’t a giant linebacker, you’re good.
Storage Everywhere (Because You Need It)
The ambulance heritage really shines here.
Original sliding cabinets retained and repurposed:
Deep pantry for food
Full-height wardrobe for clothing
Doors that stay shut while driving
Custom brass hooks throughout for:
Jackets
Towels
Hats
Daily carry gear
Massive under-bench storage in the dinette/bed area:
Linens
Tools
Manuals
Extra gear
Tall exterior cabinets for:
Chairs
Umbrellas
paddle Boards
Damp gear (with ventilation)
Smart use of every inch without feeling cluttered.
Dinette → Bed Conversion
The main living space is:
Wraparound U-shaped dinette
Custom memory foam cushions
Solid marine-grade pedestal table
At night:
Unlock pedestal
Drop table
Slide cushions into place
You get a sleeping area approximately:
7 ft long
Almost 5 ft wide
→ Very close to a queen-sized bed
Two adults can sleep comfortably. And sit comfortably. And work comfortably. Same space, zero waste.
Climate Control: Fully Four-Season
This is the backbone of the entire build. And it’s where this rig absolutely destroys most “Instagram builds.”
Cooling: 9,000 BTU Mini Split Heat Pump
Mounted clean with the outdoor unit on the rear
Runs directly off the battery bank
In summer with good sun:
Can run all day off 1,340W of solar
At temp, it idles under ~300–500W
In a 98 sq ft insulated space:
Cools quickly
Sips power once stabilized
At night:
Daytime solar charges batteries
Mini split can run through the night in reasonable temps
Can also provide shoulder-season heat, but the real winter hero is diesel.
Heat: Redundant, Smart, and Overbuilt
This rig has a layered heating system designed around:
Diesel-fired hydronic heat
Radiant floor
Forced air heat exchanger
Diesel fireplace (Dickinson Newport) as backup + booster
1. Diesel-Fired Hydronic Heater
Typical 9kw “truck pre-heater” style diesel boiler
Heats a closed-loop:
6-gallon aluminum tank filled with RV antifreeze (glycol)
Tank reaches ~180–186°F (≈85–86°C)
That hot glycol feeds:
Radiant floor loops (PEX)
Heat exchanger for domestic hot water
Small radiator/fan unit for cabin air
2. Radiant Floor Heat
PEX tubing runs through the floor, circulating hot glycol from the buffer tank.
Result:
Warm floors even at brutal subzero temps
No “frozen floor” misery
Pipes and tanks inside the envelope stay much happier
3. Domestic Hot Water (Engineered Right)
A marine-style water heater with an internal coil:
Glycol loop from the hot tank runs through a heat exchanger coil
Fresh water stays separate, safe, and potable
Also has an electric element:
Used only when solar is topped off
Turns extra sunshine into stored hot water for night showers
4. Cabin Air Heat: Hydronic + Diesel Stove
Compact radiator + fan, tied into glycol loop:
Thermostat-controlled
Quiet
Blows warm air across the cabin
Dickinson Newport diesel heater:
Simple, reliable, mechanical
Independent of the complex controls
Also piped into the glycol loop:
When it runs, it helps heat the buffer tank
That heat can go to floors + water
This means:
If the hydronic electronics ever failed, the Dickinson can still:
Keep you alive
Warm the cabin
Contribute to floor & water heat via the loop
That’s true redundancy.
Surviving Real Winter: Proven
During the infamous Arctic blast:
Only one line froze: an exposed shower line at the edge of the floor
Everything else:
Floors
Main lines
Tanks
Systems
→ Stayed functional
For a compact rig, that’s huge. This isn’t theory. It’s stress-tested.
Power System: Tesla Battery + Victron Brain
Side cabinet = the nerve center. This is where the real money lives.
Key components:
1,340W of solar on the roof
Two Tesla Model S lithium modules (≈24V nominal system)
Victron MPPT charge controller:
Custom charge profiles
Temperature-aware charging
Protects the Tesla cells from cold charge damage
Smart battery protection & master disconnects
24V → 13.4V DC-DC converter:
All 12V house loads run at a healthy voltage
Fridge, fans, pumps, controls, lights, heaters
Victron Multiplus 24V/3000W inverter/charger:
Powers:
Mini split
Induction cooktop
Microwave
AC outlets
Can accept shore power when available
Can be configured to limit input, assist loads, etc.
Insulated & thermostatically controlled battery heater pad
Keeps Tesla modules in a safe temperature zone
Ensures longevity and proper charging
All of it is:
Labeled
Serviceable
Built in a way that someone who understands DC systems can maintain
Living In It: Real Talk
I lived in this rig full-time for over a year.
I cooked real meals.
I took hot showers.
I worked, edited, slept, and rode out storms.
I didn’t feel like I was “camping” — I felt like I was home.
No:
Wet sleeping bags
Frozen floors
Generator headaches
Constant propane hunts
Yes:
Warm toes
Hot coffee
Quiet nights
Real independence
If you’re considering an ambulance conversion, or you’re trying to design a truly four-season off-grid rig, take this as proof of concept:
You don’t need huge.
You don’t need flimsy.
You need smart systems, redundancy, and a platform built to protect human beings.
If you’d like, I can turn this into a printable build sheet / system diagram so people can copy the core layout (power, hydronic, floor heat, water, etc.) for their own rigs.