truck will not crank. i put in new batteries, replaced contector ends at battery and replaced starter relay on fire wall. the wait to start engine light comes on and goes off. when i turn key i get one click. 12.6 volts on batteries.

 

Clean all your grounds.

 

And check the starter. It may be dead. How old is the starter?

 

I would have the starter tested

 

My dually cranked comically slow in the 50*F temps with two fresh, high CCA batteries with a beat starter.

Also agree 100% on grounds. Maybe new cables. They can corrode internally!

EDIT - maybe you have a bad NSS. Have you tried to crank at solenoid? Careful if you have manual.

 

Automatic or manual transmission?

Where is the click coming from? Is it a loud CLICK, or just a medium "click"?

 

i checked the grounds they look good and tight. i check continuity between the batteries and the motor it is perfect. I had the starter checked it is good. the clunk is medium and sounds like like engine compartment passenger side.
thanks for the suggestions

 

Had the truck been starting good before the problem started, or has the truck sat for a long period of time? Put a socket and breaker bar on the bolt on the front crank pulley and see if you can turn the motor over.

 

after replacing the starter relay, cleaning the battery cables and replacing the cable ends i was still having problem. i had battery tested and it tested good. I going back to the starter. I called another shop and the person there told me that the tester is a no load tester and the starter can be bad even when the machine says it is good. So I replaced starter with new one and no more problems. Ever since I got this truck 7 years ago it would crank for a while before it would start. I thought this was just a ford. Come to find out the starter was half dead since I got the truck.
Thanks for all the help and suggestions.

 

Glad to hear you got it figured out.

 

Hell yah! Easy fix