Trailer lights cutting out?

[TJL72]

So I’m not sure what’s going on with my trailer. Using a seven pin to four pin adaptor and have tried three of them with the same result. When running lights are on I get a fast left signal which throws a code in my display. Sometimes when the running lights are on, they don’t work and there is an error for them and then the left turn issue goes away.  When running lights aren’t working if I turn my lights on five or six times they suddenly start to work again.

 

seems odd that when connected it shows pin 4 active in the display as per photo but does not show the ground connected either in the four way image

[dieselfan1]

Ground issue? Longshot but

Try cleaning the trailer hitch ball if it's rusty.

[TJL72]

Yeah it was dirty and was cleaned out prior to this - I think it’s a ground wire somewhere just have to find where.  
 

if the 4 pin is connected properly through adapter should the display show that? I’m still confused why it shows the circuit for reverse - number 4 - as connected when adapter has a plastic knockout in that position???

[TJL72]

Does anyone have a screenshot of the display when a properly working for wire trailer is connected?
 

I took it one of the rear trailer lights and the ground is fine… I’m thinking there must be a break in a running light power wire somewhere. Do I just start at the front and make my way back?