Hey everyone , I have a Peterbilt 337 with the PX9 engine the truck has brand new battery but won't start. I checked the starter solenoid with the ignition on it's receiving the same amount of volts that the battery is putting out. I tried the screwdriver on the solenoid trick but no luck just a solid clicking noise coming from the starter. Currently I'm looking for a starter relay to see if that could be the cause I can't find it in the manual for the truck. Any help would be appreciated.
Pete liked to use a square plastic starter relay mounted just left of center on left side firewall. But if you jumped the solenoid at the starter more than likely a bad bar on the armature. Possibly a MT39.