i tried to start my truck today at the grocery store and had power with the key in the "ON" position and as soon as i turned the key to start everything went dead, absolutly no power to anything and retrying the key still gave me no power. after waiting for a min or 2 i could hear the guages reset like they do when you reflash with efi at the end of an upload when the computers reset and then i finally had power, so i tried to start again and the same thing happened. so after a few tries i put it in nuetral and as soon as i did all power came on, and it did start but it gave me that fast clicking sound like the batteries were dead for about 2 seconds and then all of the sudden it turned over and started.
my ecm and tcm reset along with my stereo. i know my tcm reset because my shifts were horrible like the taps were re-learning. and from the sound of the guages im pretty sure the ecm reset.
i have been having my voltage guage movining up and down from about 13-15 slowly but when i took it to napa and had them hook up the elctrical system tester everything checked good, and when i put a voltmeter on it everything is steady at both batteries and the jump point.

i beg you guys for your help. thank you far in advance

Your ignition cylinder switch might be going bad. That would be the first place I would check seeing as how the electrical system checked out and the on position worked. the Start position might be having some contact issues. Good luck.

i will check those when i get home.

i forgot that this all started on saturday after i got a car wash and it wouldnt start after they were done with it.

i think i may have found it. both of my negative battery cables are not tight at all but the bolts on the side post mounts are tight as hell.

does anyone know what kind of washer i can put in betweeen to make it tight. or some other fix?

There are battery terminal spacers available at auto parts stores. Don't just use a regular washer. Glad to here that's the problem.

thanks heymccall and everyone else. i ended up pulling the bolts out of all of the cables and putting steel washers between the bolt head and cable itself which works great. i never knew i had this problem until my truck started acting up a couple weeks ago and i have had these batteries in for 6 months.

i suggest everyone with orbital or optimas check that the acuall cables are tight not just the bolts. my truck now cranks over 5x faster and there is no lights dimming when i turn the stereo way up

That's a common problem on some gm cars as well with the side mount posts,the bolt will bottom out before the cable is tight. If you over torque the bolt you can damage the battery.You fixed it correctly.

My RCLB does this intermittenly, it is time for new batteries for mine. This spring when i first got it the truck would barely start when cold and the clock would reset to 12:00. I have found if i fool with the key fob and cycle the lock/unlock several times before starting it cold it will do exactly what you said. After letting it sit several minutes it will fire right up. The batteries are whipped in it, getting time to think new.