Hope you guys can help me on this one.

Here's the background. I got my truck detailed today. Left there, drove for 15 minutes, parked the truck for 45, hopped back in and the relay started buzzing. It comes and goes and even does it with the ignition off. The buzzing goes away when the T/S switch is activated.

Only electrical mods were installing the factory 7 plug trailer kit and a Tekonsha controller with plug-in harnessabout 6 months ago.

I changed the relay with a new Ford but no change.

Of course, I have to leave for a 21 hour trip in about 16 hours....

 

sheeooot. Wouldn't you know it, dig out the test light and the problem automagically fixed itself. I guess the truck saw the look on my face and didn't like the prospect of me poking it