Have an '03 Lariat with no power to trailer connection. Checked all fuses in panel in front of driver's side firewall; all good. Interchanged the relays in same panel. Have ground continuity at pin jack but no voltage on any pin with ignition on and turn signals, brakes, etc. actuated. Exposed wiring looks good; haven't removed any of the corrugated conduit to check inside.

 

That's your next point of diagnostics.

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