only Marker rear lights not working

i agree with you, I’m going to the Tampa Freighliner they have one there, they call it a receptacle

 

Put a tester on it and yes one of the Pins isn’t working, hopefully just a lose wire in the trucks receptacle. #### that receptacle is definitely
On there tight with whatever silicone they used. I’ll try to carefully cut through the silicone in order to get the receptacle off and take a look at the wiring.

 

thank you ladies and gents, got it fixed, loose wire in the trucks receptacle!! Added some
Good weather resistant silicon to protect the wires!! I appreciate all the comments!!! Keep helping each other and everything will work out!! God bless and be careful out there.