2009 Chevy Medium Duty 4x4 Kodiak Ambulance conversion


I guess it's time to come out of hiding. I've been postponing this write up for a while now.
The truck has been sitting in my Dad's back yard for a couple of months before I could get to it. It gave me plenty of time plan and then change plans, repeat.

A few words on why I ended up with this one. I've always thought an ambulance would make a great platform for a camper. Several years ago I climbed all over one and decided it wasn't worth raising the roof. It was about 4" shorter than I was and would have been a considerable amount of work to raise or cap. That combined with the lack of load capacity and relatively small space made me keep looking.

Recently, when I decided the Firstroamer wasn't big enough the search was on again. The leading contenders were the large European expedition trucks and the Fuso. I was leaning towards the Fuso when we had to get towed in my friends sprinter van. The driver showed up in a Medium duty Chevy C4500. We rode in the back of the crew cab and were duly impressed. The size scared me until I realized they have many different wheel bases. First I started looking at putting a total composites box onto the back of the chevy. It didn't take long to stumble upon the C4500 ambulance. And when I say stumble I mean about a hundred hours of sitting in a dark corner staring at a screen.

It took another couple months for the right one to come along. I had a list of about 20 used ambulance sites to peruse daily. When I found this one it only took two hours before I had money down on it.

Now onto some specifics. Rather than talk about why I chose this over another platform I'd rather just list some features. The truck was originally purchased by Yellowstone National Park. It currently has 15,000 miles on it and is like new. It has a duramax engine that puts out 300hp, allison 6 speed automatic transmission, 4 wheel disc brakes, power windows, door locks, and mirrors. Heated mirrors, cruise control, exhaust brake (turbo vanes), air ride seats and is actually quiet inside. It's four wheel drive with great gearing and at least one limited slip axle. It has locking hubs which is both good and bad. Good because it helps with the fuel mileage (11.81 from Houston to Tucson) and bad because I use 4x4 a lot and don't want to get out all the time to lock them in/out. The truck is powerful and comfortable to drive. The transmission is a wonder. I especially like how it slowly downshifts when I let off the gas coming up to a light. You barely need to touch the brakes. Now onto the box. It has a pass through that can be done while keeping your feet on the floor. It's only about 4 feet tall, but sure beats a crawl through. Most of you already know how well the ambulances are made, very high quality and the wiring is top notch. Built in storage everywhere. Some of it will be used for systems like the electronics which will all be located in the front drivers compartment. There is rear heat and a/c, an inverter, powered vent, fan, lights everywhere, and plenty of built in cabinetry if one wants to use it. There are many other options like back up camera, 50 gallon fuel tank, rear air suspension, but I can see myself starting to ramble so lets move on.

Back in the day I had a custom shell built and mounted it onto the back of my chevy blazer. I ended up with an underpowered, poor handling, strange looking creation. And I loved every bit of building and using it.
I've always wanted to build another. Not rebuild, but do the whole inside exactly how I want. That time has finally come. I find myself in the position of having both time and budget.

I'm planning a higher end build with all electric except for an espar heater. The layout will be raised bed in the back, corner dinette, 4' counter, shower and toilet in the pass through.
Screenshot from 2018-03-24 16-36-00.jpg
I've only been at it for a week now. Many pictures to post, just don't want to spend too much time on the computer rather than in the truck. I've learned so much from this forum. I hope that continues and maybe, just maybe someone else can use an idea or two of mine. Looking forward to the comments and suggestions. Much more to come but for now more pictures then time to get back out there.
That's a shot of what started it all. It's from orangework.de If I can make mine look anything like that I'll be a happy camper. :)


Getting Started

I made some scale drawings of the truck before I left it. With these I was able to get that sketchup model going. This is also how I figured out which solar panels would work. I wanted to get as much solar up there as possible. I hope to automatically divert excess power into the hot water tank (also heated from engine) or back to shore power when all other needs are met.

This was the winning combination until yesterday. I found a larger Bomar Hatch on sale at Defender.com. Luckily I kept the "panels" so I can figure it out again.

At the beginning, and just starting to get an idea of what I'm in for. I learned something very important right away. Something I never got while reading here. I thought the interior was made from MDF. Turns out it's all some sort of SIP or structural panel. As soon as I realized this it was decided to save as much material as possible for behind the scenes structure. Does anyone know what this material is? It's a dense foam impregnated with fiberglass with laminate sides. I don't want to use plywood for this build. So far I'm planning on using king starboard. Anyone have experience using it? Comments?
You can't do an ambulance build without showing off the electrics. Working with this stuff is my version of doing jigsaw puzzles. I love figuring it all out.
The beauty of all that wiring is that most of the wires I'll need are already pre-run. Take the back of the ambulance for example. I'll want a dining light, reading lights, and a disco ball of course. To choose from is 1, left side dome low. 2, left side dome high. 3, right side dome low. 4, right side dome high. 5, rear flasher. 6, rear fan. 7, rear exhaust fan. 8, right rear flasher. 9, left rear flasher. 10, cot light. 11, check out lights. That doesn't even include the wires for the lights that I will keep like the rear flood lights. The short version of that long story is that I will have very little wiring to run and it's just a matter of changing the labels and moving a few switches. I know, it's always easy to do with a keyboard.

More progress.

A main concern is that wiring panel. I REALLY want to put a shower in the walk through. Water and power don't mix well so my plan has been to....... wait for it........... move the panel into the front drivers side box. If this doesn't happen there will need to be a major overhaul in the design dept. Most of the early tear down is geared towards answering this question.

Hang on, a short tangent here. While searching for a picture I ran across this shot. This is the sprinter I've been traveling in with a friend. We got tired of not knowing how much water was left in the tank so she bit the bullet and bought a piece of 6" clear PVC. And it was only 65 bucks per foot, ouch. Anyway, tangent over, I just wanted to show this off.

Tearing more apart to get to that electrical wall.

A shot of the hardware removed so far. Another savings bonus I should be able to put most of this right back in.

That's it for now. We are almost live. Just a bit more to post, I'll try to do it soon. In the mean time one question for the masses. I'm trying to decide on a ceiling material. I want something light in weight and color. Also considering a piece of dark wood going up the center that's back lit.


I’ve been following closely on Instagram!!

My first ever car was a black 79 Blazer
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kodiak guy
awesome, finally get to see pics of your rig! that is just about a twin to mine - built by wheeled coach? in your email you said you moved the electrical panel to the compartment 1 do you have photos? i was trying to figure out how you did that, all i could figure to do was move the stuff at the bottom and then cut the bottom foot of that board off to drop it down.

enjoy - another thing i did was found that the speakers are just inserted into those bumper mounts ... you can pop the speaker out then re-use those for lights. i put my turn/marker lights in there along with a 4 LED cube (amber fog light)


Thanks, I started reading your build thread today after I saw your signature. For some reason I'd missed that one. Thanks for posting it.


Moving the electrical panel into the front drivers side box.

This one's for you Jim.
Yes we do have almost identical vehicles. Mine is a Wheeled Coach as well. I assume your interior was made from the composite panels as well? Thanks for the tip about the front speakers. You probably saved me 30 minutes of trying to figure out the magic of how they were attached. Now I can just bonk them from the back.

The first part was getting enough slack in the wires so I could move the panel far from the wall. Some space was going to be needed in order to lift the panel up and put it into the hole.

Cutting the box was much easier than I figured. A sawsall with a good metal cutting blade does wonders on aluminum.

Two thumbs up for Wheeled Coach's electrical team. I didn't have to cut and splice one wire. Each one had enough extra length to be able to lift and drop the panel into the new spot.

After it was in place I realized that they must set these up to optionally go in either spot. The board fit like a glove in the new spot and I will only need a 3" hole in the top and bottom corners for wire runs.

Since the panel move I ripped out the ceiling and put up all of the extras on ebay. Saturday was a shopping spree online. It's amazing how much time it takes to find all the right doo dads. This job would take half the time if there was a "build your own camper with quality parts store" next door. Tomorrow will be spent in Tucson buying more parts and some tools. Tuesday I go back into attack mode. Shower pan coming soon, hopefully.


This is almost identical to mine too - 2009 Kodiak, 2 door, 2wd, Osage box.

I wish I was up for as much punishment as you are with the electrical system. I don't want to move it at all I am still at the stage of figuring out how to get electrical in the box to stay hot while the truck isn't running.
I also have some work cut out for me to figure out why there are apparently 2 converters (battery chargers) on there yet the battery doesn't seem to charge when on shore power.
And of course, there is the solar that will need some experiments too.

Fortunately though, despite all this lack of know how and learning; my rig, which I got 2 months ago has been on 3 trips! I'd put in more time this weekend except I'm planning to take it out into the wilderness again :)


rossiter78, There's something to be said for just using the darn thing. I'll be spending hours and hours working on mine while you are out there enjoying life.
On mine everything is controlled by relays and solenoids. There is one main solenoid/relay that allows the batteries to energize the board. Get power to that one and whabaam, power to the coach. I'll need to rewire mine as well. Right now I can only activate the master switch for the rear when the truck is in run or acc.
Good luck with it.


rossiter78, There's something to be said for just using the darn thing. I'll be spending hours and hours working on mine while you are out there enjoying life.
On mine everything is controlled by relays and solenoids. There is one main solenoid/relay that allows the batteries to energize the board. Get power to that one and whabaam, power to the coach. I'll need to rewire mine as well. Right now I can only activate the master switch for the rear when the truck is in run or acc.
Good luck with it.
Is this a solenoid?

In some google searches it looks like it makes a connection when the green wire has power. This is what I'm planning on testing out to see if that puts power to the box.


I'm going to say yes even though I've never seen one like that. Can you check it by throwing the switch and testing for voltage before and after. Mine look like this.
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