Fuse box diagram 2003 Kenworth

Wonder how similar the 01 T2000 is . . .

You're talking about the glovebox location, right ?

 

If by "front marker light" you mean the tri-angle shaped turn signals that are mounted right beside the head lights, they are NOT markers from the factory. They blink when turning only by design. If you want then to light up as a marker you will have to splice into the harness going to the little side marker on the bumper to get power. The factory harness is a 2 wire harness going to that light, you will have to change the socket and bulb from 1156 to 1157 even if you are changing to the LED conversions they come with a 1157 type connection. I hard wired mine but had non-stop problems after the second year, got tired of fixing it so put a brand new factory 2 wire harness back on it and went back to turn signal only.

 

They could be ordered from the factory with a 3 wire function,my 03 t600 has it.

 

There isn't a fuse just for those,they are on the same circuit as the corner lights on the bumper & your taillights.
I can look in mine tomorrow if you want.

 

Have you checked the bulbs to make sure they are good?