Tail light problem

54Hollywood

Hi everyone.  Have a tail light issue that is driving me a little more crazy than usual.  Left rear tail light bulb went out.  Replaced it with the correct bulb but now I only get either the regular tail light or I get the turn signal/brake light.  Not both.  Pulled the socket out and checked it with a trouble light and I'm getting good current to both contacts; tail light and brake/turn signal light.  But with the bulb in, I only get one or the other and they only light up the same filament in the bulb.  I'm pretty sure it's a grounding issue but I don't know where to start.  Everything looks good but...  Appreciate any suggestions, thanks.

Tim in WI

Geoff

Definitely a grounding issue.  Clean the area where the mounting clips into the frame. 

54Hollywood

Thanks Geoff.  I'll work on it.

54Hollywood

Right on the money Geoff.  I had cleaned the contact areas of the housing but I guess not good enough.  Worked on that again and now the lights work great.  Thanks again mate.  

Geoff

What happens with no ground, the only circuit is through both sides, hence all filaments glowing slightly.   Tricky to understand!

54Hollywood

Or in my case, only one filament worked and it was the same filament for either the turn signal/brake light or the running light.  Tricky indeed!  Thanks again.