Medium and Heavy Trucks
Have Truck Repair Questions? Ask an Expert
Are you jumping through the battery? Try jumping at the starter solenoid, if battery has bad cell, you can't jump through it. And with voltage at 10.37, you may have a bad battery.
How much trouble is it to install you truck battery and try it. I still think it is battery voltage,
Sorry for late reply, Had to take wife to Dr. what is battery voltage in, to have 3-4 volts out? The output of the relay/solenoid should be the starter motor.