Isuzu Trooper Engine Not Cranking Over

My 2002 Isuzu Trooper Just Goes Click, Click When I Try To Start It. I Have Replaced The Battery And The Relay But No Change. What Could It...

Just Bought 01 Trooper Engine Will Not Turn Over When You Try To Start But Is Not Locked Up. Flywheel Can Be Rotated From Access Panel...

Car Still Turns Over, But There Was A Burnt Wiring Smell And It Just Lost Power...any Ideas Where To Start Looking?

Did A Head Gasket And A New Cam Did The The Timing And It Have Fuel N Spark But Doesnt Seem To Turn Over And Run..not Even A Bak Fire.....