Just off the phone to RV Autos ( no connection) regarding my mot that is due in a couple of months and guess what I have a side marker out, asked the question and YES they are included in the mot. Mentioned about this discussion HIS reply "aye there are a lot of Internet experts out there" had one of these twats here the other week telling me how to do my job, he was sent packing with a FAIL !
Perhaps the next time you see him you might ask him exactly where in the testing manual does it require side markers to work. I suspect he's either fallen foul of an acquired 'bad habit' or he's testing your van as class 7 or other goods vehicle (for which side markers are required if over 6m long). The thing about "internet experts" is that they are capable of working from first principles by referring to the actual legislation (e.g.
@wildebus in post #41) and the MOT Inspection Manual -- which defines the items that must be tested.
I linked the passenger vehicle manual upthread.
Here's a link to the HGV manual (PDF). Section 63 states that side marker lights are required for all vehicles over 6m long, viz:
The inspection of side marker lamps applies to all obligatory side marker lamps fitted to vehicles and trailers.
Side marker lamps must be fitted to:
• vehicles with an overall length exceeding 6m first used from 1 April 1991
• trailers with an overall length exceeding 6m manufactured from 1 October 1990
• trailers with an overall length exceeding 9.15m manufactured before 1 October 1990
However, even that says inspection only applies to
obligatory side marker lights -- and they're not obligatory on passenger vehicles and so do not need to be inspected.