Rear Lights

[Matt_305]

This is the last thing I must do before sending my truck for inspection bodywork and paint etc. On the drivers side only the marker works, on the passenger only the taillight, no brake lights, unsure of reverse but I believe they work (don't have any single contact bulbs). Sockets don't seem to be bad (checked them with a little tester). Could it just be these sockets grounds gone bad? Probably sound like an idiot but ah well, just excited to be near completion and want to do it all correctly. Thanks,
Matt