First, Welcome !!!!
The Light Problem........
The OEM lights have a separate turn signal circuit/lights.
If he "married" them, you could be having feed back into your lighting circuits!!!
A quick fix is to get a flat 4 pin trailer plug "Adapter Kits" that will get your separate turn signals to
run a standard trailer 2 light system.
Follow the mfg wiring diagram, then hook up the lights that "He" made.
Hope this works.......
CAPT