Bad news/good news
 

The V70 went in for its M.o.T. today which[as I knew it would]it promptly failed.The failures were 1] Number plate lights not working.I knew they weren't but after fitting new bulbs a week or two ago and these not curing the problem I thought before delving deeper I'd submit it for test to see what[if anything] it would fail on,which it did.2] is that the n/s bottom balljoint is worn,luckily I have a pair of new bottom arms "in stock" and that's the sum total of failures so I'm happy with that,no straight pass obviously but as failures go nothing frightening/expensive/beyond my capabilities to sort out-although car electrics are something of a black art to me even I can manage to bridge a couple of wires together.

A cheap testlight is easy to buy or make, around £6.00 will get one from a certain auction site. This will allow you to probe the numberplate light fittings and work-out whether you have power there or not, also can be used to see if the earths are any good by feeding the testlight with 12v from the vehicle battery.

Most likely scenarios are either a poor tailgate harness near the hinge or at the connector just inside the car/headlining (easy fix) or possibly duff numberplate light units (easy fix); the latter can get a bit corroded on some V70's when the water works it way inside from above the unit/s.

Last Saturday put on new lower arm[then did some work on the Omega]on Monday worked out there must be a break in the wiring[probably around hinge]connected a "bridging wire" from block connector behind rear pillar trim to wiring on taigate-so bypassing likely areas for breakage,lights then worked as should.Today took it for re-test and got a pass,so legal for another year.