1992 6.5 diesel wont start when i go to try to start it you hear a humming sound. so i went to try it again it started right up now its doing the same thing again.???

i have checked the batterys
its not locked up

 

Does it crank over or just dead?

 

Check to make sure battery terminals are clean and ground cables are clean. Need more info though to give better advice

 

It doesn't crank at all jus like a humming sound

 

Could be several things. Check positive cable connections at the batteries and at the starter. (My money is one the positive stud on the solenoid and/or the starter housing to the block.) Remove the starter from the block (you don't have to unhook the wires) and check the cleanliness of the mating surfaces. I recommend cleaning and coating with dielectric grease prior to reassembly. Also use dielectric grease or NLGI-2 grease to coat all connections you clean.