No Power At Fuse Box for Trailer Lights

[jkrosky]

I have a 2017 Chevy Silverado 3500 HD High Country with 6.6 diesel equipped with tow package.  It has dedicated trailer brake and trailer fuses within the primary fuse box under the hood.  My passenger side trailer blinkers and brake lights are not working.  I've traced the lack of 12v power all the way up to the 10a fuse dedicated to the right side trailer brake/signal light (fuse #17).  I have replaced the fuse, re-tested, and still no power.  The left side trailer brake/signal light (fuse #14) has 12v power going to it, tested on the top of the fuse when the flashers are on, but the right side has nothing.  I've also swapped and then replaced the trailer parking lights relay switch (relay #63) and still nothing.  Is this most likely an issue with fuse box or something else supplying power or ground to the fuse box?  Thanks for the help... this is the craziest thing.

Edited July 15, 2019 by jkrosky

[JD110]

Turn Signal Lamps

For turn signal lamp operation, the left and right trailer stop/turn signal lamp relay’s are supplied with battery voltage at all times. Ground is applied at all times to the turn signal/multifunction switch. The turn signal lamps may only be activated with the ignition switch in the ON or START positions. When the turn signal/multifunction switch is placed in either the TURN RIGHT or TURN LEFT position, ground is applied to the body control module (BCM) through either the right turn or left turn signal switch signal circuit. The BCM responds to the turn signal switch input by applying a pulsating voltage to the left and right trailer stop/turn signal lamp relay control circuits energizing the relay’s in an ON and OFF cycle. With the left and right trailer stop/turn signal lamp relay’s energized, the relay switch contacts cycle ON and OFF applying battery voltage through the left and right trailer stop/turn signal fuse’s to the trailer turn signal lamp control circuits which illuminates the trailer turn signal lamps in an ON and OFF cycle.

Maybe the fuse relay center, check for power at the relay.