No you won't for this purpose, just turn your headlights on and everything will work on the van as it should, the only light that won't work is your trailer indicator on your dash.
Once you sort everything else out then you can look for a device for the lights, the device for the D4 is a little cheaper and less complicated than the one for the D3, the D4 doesn't flicker like the D3 does when LEDs are involved.
Go down and speak to the guys at Mitchell Bros in Brookvale, they should be able to help you they are at 16 Chard Rd, Brookvale.

