2011 Peterbilt 387 not starting

You might want to check the connection on the starter. They do corrode there. If that connection is clean, remove the second nut on the same post. Push the bolt in and give it a half turn, pull it back out and assemble the rest. That copper bolt is the contact for the starter. When it spins, some of the bolt head wears off, until it can not longer make contact. If that works, buy another copper bolt and replace it when you get a chance. My dad taught me this years ago an I have done it plenty of times. The good part is that it only takes a few minutes and there is not cost.

 

Pretty sure the starter it’s self is done.
Check the started solenoid should be on the fire wall.

 

I had an auto shift that would not crank with key so I crossed out the starter and cranked it to get it home. Neutral safety switch was bad.

 

Can u help locating my starter relay 387 2007 , have same problem starts when cool , wont start when hot , over crank bypassed

 

Underhood chassis load center right hand side firewall under air cleaner.

 

Cant find it, by air cleaner u mean the filter?