The left turn signal and left brake light are not working on my trailer. It is the same on two different trailers. There is no power on the left turn pin. Right one works fine, but noticed low voltage on it.

Checked the main power pin (1:00 position), and it only has 2.8 V.

Checked fuses and they appear fine.

Suggestions on where to look next?

 

Do you have the factory towing package or an aftermarket wire harness that plugs into the tail lights wire harness?

 

Factory wiring I believe.
verified that 2.8 volts at the red and white pins on the connector that plugs into the receptacle,

so nothing going on in that connection