tripac apu troubleshooting help

not sure if this is the right place to ask or not but i just bought a 07 kenworth with a thermoking tripac apu the unit will crank but doesn't start. everything i've found online pointed to the fuel pump but that didn't fix it so i checked for power and ground at the fuel pump plug and am getting continuity to ground on both wires. after following the wires an not finding anything cleary wrong or shorted i i unplugged the fuel shut off solenoid and the continuity to what should be the positive wire at the pump went away. does this mean the shut down solenoid is bad? i've searched online and unable to find a wiring diagram since i don't know the exact model of the apu

 

i guess i didn't realize that was a option. but since it should be spring loaded outward i guess that would make it start. i will have to try that tomorrow i've looked all over for a wiring diagram with no luck even called the thermo king dealer but they said i had to buy the manual and wouldn't give me any info
thanks

 

i'm still confused as to why i have ground at both wires going to the fuel pump if the solenoid is plugged in.i've worked on small diesels like this before so know the basics.it's a 3 wire solenoid ground,pull and hold in my mind the fuel pump would run off the same wire as the hold coil which i assume would be fed thru the safety switches and if the solenoid was the last thing before the fuel pump that would explain why the ground on the positive wire goes away when i unplug it. then again if anything is shorted i would expect to find a blown fuse and i haven't so far. once i figure out which model it is i may have to buy the manual so i can get the wiring diagrams. i'm just stating to build the truck haven't even started school to up my licence yet so i'm not in a huge hurry. i'm picking up the bed in 2 weeks and plan to run my pickup untill the end of my before hitting the road full time with this rig. i just i should have explained i haul campers for a living and after 9 years and almost 700k miles on my pickup it's time to up my game. the t600 i bought is a box truck with the studio sleeper and i'm pulling the box and installing a flat bed so i can haul 1 camper on the bed while towing another behind me.twice the pay, twice the hours of service (when the wife is with me) and no more hotels. only downfall is the #### eld