T660 - Side Light / Blinker

[JKBowman]

Something ain't right. :-/

Wifey-Poo noticed these fender lights (both sides) were burning very dim while parked. Blinkers still worked, but soon after we started getting a fast blinker signal (both sides).

A shop looked at it and suggested that the seats for the steady-burning bulbs (OEM is a two bulb unit / one blinks - one burns steady) needed to be replaced.

The replacement I chose, a Union Pacific LED contraption, is what you see here. Thing is, the steady burning function is still incredibly dim. More than 5 feet away and you can barely see this.

Photo is with headlights on.
I get nothing (zero) with just parking lights on.

Question:
- How can I get a wiring diagram for this?
- If it was your truck, would you take it anywhere other than Kenworth to chase this down?

Two shops without schematics have now looked, albeit briefly. Neither charged me for the quick look, but the second one said, "Man, we just don't have the schematics."

That's why I'm asking.