Toyota Repair: starting issue, volt ohm meter, fuse box


Question
I have a 1999 Camry,LE. 333,333 miles. 2 months ago the car would not start on the first attempt,or second attempt. At times it would make a "click" noise" at other times "no noise". I cleaned the battery posts. No more problems until a week ago, the same thing started. Battery posts only had a small amount of build up, they have been re-cleaned with new cable terminals, which are tight. But,the problem persists. When attempting to start, I hear either no noise, or a "click". When turning the key to the "start" position, all dash lights go off, then turning key to "off" position and an attempt to restart is successful. It has successfully started on the 2nd or 3rd attempt. The battery is 18 months old, voltage check reveals 12.4 volts.
I am puzzled, please help with any guidance you have. This is my wife's car which she uses for transport to and from work.

Answer
Herllo, we can safely assume that the battery is not the problem, when the dash lights turn off like that there is a loss of voltage between the battery and the positive wire going to the fuse box, you assured me that the terminals are also not the problem. Check the negative cable from the battery to engine or frame ground, make sure the ground connection there is good, if that seems ok we would need a volt/ohm meter to do a couple of tests.
In the fuse box under the hood is a large 100A alternator fuse, make sure this fuse is not loose.