Problem just started yesterday, starter will not turn over with key and I've been using jumper cable to starter stud to crank. I have a Chilton but its not real useful with diesel but it did say the starting relay maybe bad but no pictures were it is located? Anyone know.......checked with local auto parts and they sold me one but did not see under the hood on fire wall or fenders?

 

Found the problem, the ear on the key lock cylinder in the stearing column broke, replace lock cylinder now working fine!