2002 Mazda B3000. Clicks once won't start

It could be the starter, or it could be just the starter solenoid. You can do a voltage drop test at the starter to make certain that is your problem, as it can be expensive to replace parts without an actual diagnosis.

try and jump start it first after you/someone checks all battery cables /ends/grounds..if after your confirm all good connections and battery load test/starter draw ....so..if it wont jump start ..replace the starter..also check starter gear and flywheel teeth and alignment of starter

Ken, thanks for answering my question. How would I do a voltage drop test? I drove this truck from Reno, Nevada to Cocoa, Florida with two cats in it in the height of summer, never ever do that. Didn't have one problem, In fact I haven't had any problems with it til I got to Florida, maybe it likes Reno better. Any and all suggestions are welcome.

Gonna try to jump it as soon as I can get someone over here to do it. Thanks

Couple links for voltage drop tests; http://www.aa1car.com/library/voltage_drop_testing.htm , http://easyautodiagnostics.com/misc-index/starter-motor-on-car-tests-1 , Basically you want to determine is proper voltage is getting to the starter solenoid when turning the key

Could it be that the starter fell out of place and just need to be sort of 'knocked' back into place. I've had this happen.