The battery in my truck turns the motor over plenty fast enough that it should start. However, it will only start with jumper cables on it. Any clues?

 

Sounds like you need a new battery ...

 

yeah definitely replace the battery. I had the same exact problem in my truck.

 

I am fairly confident the battery is not the problem. I have tried quite a few, although none were brand new, they were known, good batteries. I am having some other electrical issues as well, but would like to figure this one out first..

 

clean the connection between the terminal and battery. also check your battery wires. alot of times they corrode under the wire wraps

 

chances are that you have corroded/dirty terminals and or battery cables. you won't be able to get good amperage from the battery through the cable.

 

Plenty of amperage. Motor turns over pretty fast and it will start on its own occasionally.

 

started at the battery cause there's nothing left to lose. Replaced wire to starter with marine grade high zinc wire from a boat. Cleaned battery wire ends to the relay/EFI fuse block thing on passenger inner fender then it ran perfect. Drove it to the garage from the back yard and let it get warm. While warming up I started bolting the relay block EFI thing back on the inner fender and when I grab it the motor bogs down...Might have this thing licked tomorrow.