No reverse lights, 82 cabby

Finally got round to sorting electrics out for mot but only think I can't seem to figure out is the reverse lights. I checked the fuse, all fine, check bulbs all fine. Went to the switch on gear box, has the 2 spade one, pulled the wires off and checked for volts but neither wire is giving out any power. Followed the wire back into the car but can't see anything. Any ideas. Also I read reverse lights aren't checked at mot, this true? 
Thanks in advance

I've been playing around with my reverse lights today, mine turned out to be a faulty gear box switch. I tested it by touching both the spades together if lights come in then switch is faulty, otherwise check all connections at rear lights I've found them to be really tempremental and spent a good time cleaning all connections with wire wool. 

follow the reverse switch wires back, on most mk1 there is a 2 pin plug on the lighting loom which the reverse switch loom plugs into, this connector is not sealed and neither are the reverse switch spades so corrosion can build up

Did originally try the switch by bridging the two spades together but still nothing but I am only getting 1-2 volts so probably corrosion build up on the lighting loom will investigate at weekend 

Just an update. My reverse lights now work it was the 2 pin plug adaptor connecting to wiring loom, one of the pins had corroded and snapped. My connector was located under the washer bottle, I has to remove it to gain access. A very easy job thanks rubjonny 

coolio