Won't turn over

[Dvskate]

Hey guys my boss has a 2008 f450 6.4 towtruck and it has been having
This problem for maybe 3 months now randomly not starting some days and starting fine others. Now it won't start at all unless I turn the key to on and jump the brown/ green wire going to the starter solenoid. It has a sct programmer on tow mode, egr and dpf delete. I replaced the ignition switch and i have power at the relay and everything just no power going to the starter when the key is turned over. Any ideas? Thanks in advance.

 

[webb06]

Check the exhaust sensors located in the exhaust pipe where the dpf used to be. If one if them fails then it won't crank.

 

[Dvskate]

Well it ran with the dpf one not in just idled high when the dpf delete was done because they sent the wrong pipe but how do I know if one is bad?

 

[webb06]

You can usually monitor the exhaust temp sensors via a scan tool and if its reading 0 or way high like over 400 then it's bad

 

[Dvskate]

Ok ill check that out thanks

 

[Will@Rudy'sDiesel]

Did you leave the sensors unhooked? If you did then it will idle high with an SCT. If you run the H&S or the spantan however you can leave them unhooked. Try taking all the sensors and plugging them up, then zip tying them to the frame and it should fix the high idle.