Hi hoping people still frequent tis forum, been a while. Always helpful here.
67 Firebird, updated all electrical 2 years ago (American Autowire) Everything was working great.
Noticed my rear tail lights were out, but Brake and Blinker work perfect.
The Fuse for "Parking Lights" is blown, and blows instantly when turning on the lights.

So how do I find the Short? It coiuld be in the Switch, or any of the light sockets, but all wires and sockets are new.

I've read aboiut tricky ways to find a short, I have a test cable made up, base on someone's design, aligator clips on each end of a pair of wires about 20ft long.

Any tips on finding where this short might be? I've got a new boxes of 10amp fuses coming today.

Any help appreciated.

Thanks