A basic electrical system consists of the following components:

* secured wiring engine compartment - living space

* 12 Volt interior lighting

* 12 Volt plug for coolbox, for example

* 220 Volt transit network connection via the Extent (!)

* 220 Volt connection

* USB connection

Mickel Moen maintains a very informative blog about this topic:

https://mickelmoen.blogspot.nl/2014/05/alternatieve-schemas.html

An important electrical component is the refrigerator / box.

We use the Transporter throughout the year, around 90% as a luxury passenger car.

For us it makes sense to use a cool box.

A built-in refrigerator is possible: plenty of space in the Extent kitchen unit.

The 220V throughput for mains connection is very easy and practical via the Extent!

So sawing in the body is unnecessary!