Rear lights popping??

Trying to get my mk1 on the road after 3 years being sat….. All going well, starts good, runs sweet. BUT. My rear bulbs keep popping, the guys at work think it may be a duff earth wire, but I've checked the ones that come from the rear lights to the floorpan next to the spare wheel well, sanded the paint off it, there's good contact there, any ideas what it could be??

The problem seems to be when you put the hazards on… They sill be fine, but once you put hazard lights on it blows right rear side light, indicator, and brake lamp.

Help is much appreciated guys, 

Cheers
Rich

have you got the correct dual filament bulb in for the stop/tail? cant really think what else, bit of a random one really. even if it was an earth the bulbs shouldnt blow as they're designed for 12-14v anyway regardless of how it gets there…

have you checked alternator output, maybe its too high?