82 Seca Taillight Troubleshoot

Ok so my 82 Seca taillight isnt working. No power when using a meter on the connector from the harness to the taillight/break light but there is power to the license plate light which runs off the same connection. Just wondering if anyone has an easy fix before I delve into this further. Thanks for looking!

 

here is a 550 wire dig. what size is your bike?
http://frankjohansson.com/stuff/xj550/XJ550 ElectricalDiagram.html

check fuses do you still use glass ones? could be loose get an inline fuse holder and put aligator clips on it to make the connection across the clips
the taillight and brake are simple circuits. for the tail light, follow voltage from main fuse to connector up to key switch then back down to lights
problem could be the fuse clips ,large connector under the tank. connector at ingition switch, dirty connectors at tail light. are your bulbs good?

at some point you should replace the glass fuses with a box or inline fuses blade type
http://www.xjbikes.com/forums/threads/how-to-install-an-aftermarket-fuse-box.6350/page-2#post-432496

 

a easy fix would be to check the bulb