Best way to locate a fault in garden 12v lighting

[marconi]

Did you obtain access to the T connectors - see #8.

Have you taken each fitting and powered it alone from a known good psu?

 

[captaincaveman]

Did you obtain access to the T connectors - see #8.

Have you taken each fitting and powered it alone from a known good psu?

Alas none of the T connectors are accessable. Even the few that I can see are out of reach :/

I suppose I could take each fitting out to test by snipping each cable. I'd have to clamp all the cables to stop them retracting back into the wall (& have decent weather!). I'll ask the customer if they are prepared to pay £130 per fitting that's faulty and the labour charge on top (plus ££ for parts making new weatherproof joints)