David Lawson's Fahrzeug (#1275)

The coronavirus has affected my income. Its time for austerity. Things will progress very slowly for a the foreseeable future. I'm still working on smaller pieces as finances allow.

General Information

Manufacturer and model Ford F-550 chassis cab
Name Mad Maxine
Country USA
Year of manufacture 2019
For sale? no


Engine type TurboDiesel
Cubic capacity 6.7 liters/406 cubic inches
Number of cylinders 8
Horsepower 330 hp @ 2600 rpm
Torque 750 ft-lb @ 2000 rpm


4x2, 4x4, 6x6, 8x8 4x4
Wheel base 205 inches
Number of seats 2
Rim size 19.5 inches
Type of tyre medium duty truck tires
Tank capacity 26.5 gallon factory installed center tank and 100 gallon aux tank
Diesel filter yes
The truck has been ordered without the rear fuel tank. Extra fuel tanks will be added in a different location.
Permanent or manually selectable 4-wheel drive manual 4 wheel drive
Diff locks Factory rear limited slip and Eaton eLocker4 manual front


Manufacturer of the cabin myself
Cabin material Steel frame with aluminum skin
Number of beds one

Refrigerator; cool box

I am experimenting with converting a small AC toploading freezer to an inverter powered refrigerator. So far, the power usage is extremely low. If this works, it will be 1/10th the cost of a dc refrigerator half its size and it can be replaced most anywhere in the USA. The external thermostat is a Johnson Controls A19AAT. I'll clad the top with linoleum or wood and use it for a table top so the space is not wasted. A hard start capacitor and a soft start circuit was added to lower the inrush current on startup. This allows the use of a smaller inverter. It now uses an average of six watt hours continuous and 425 watts on start up. The soft starter controls the startup with an initial 20% voltage which ramps up to 100% over five seconds. The hard start capacitor helps with the reduced voltage.

I think this experiment has been a success. It is low cost, easily replaceable with off the shelf items, has a high capacity, and has a low power drain. I'll tidy everything up and add a trim plate to the open hole left from removing the original thermostat. My intention is to power this with its own small, modified sine wave inverter. These are available almost everywhere in North America.

Power supply

Voltage in the chassis 12 volt and 19 volt
Voltage in the cabin 24 volt
Charging converter 24V-12V 12v-24v
110V / 230V in the cabin? yes
Inverter I'm looking for an inverter that is not screaming with rf.
The circuit breaker is installed on the bumper because there is just no room under the hood of a 2019 F-550. Two 2/0 cables are attached to the starter battery bank through a 1/8" x 1" copper bus bar. Power is taken from the circuit breaker to the SB350 connector through a 4/0 cable.

A 12 volt outlet was removed from the dash. This circuit now powers a relayed 12 to 19 volt converter for laptop use. An XT-60 plug was used to keep the 19 volt connection unique.

Water system

Capacity of fresh water tank(s) 100 gallons
Capacity of waste water tank(s) 40 gallons
The highlighted pieces of the rear fuel tank have been ordered separately. It will be converted into skid plate equipped gray water tank.


Manufacturer and type of toilet Thetford cassette

Vehicle accessories

Extensive radio equipment to be installed in area of factory console.
released 20.10.18 
owner David Lawson 
views 6929 
filled out 60%