Went to start my car[72 Chevelle] the other day and...Turned the key,the idiot lights came on but when i went to start the car all the electrics went dead. I have plenty of battery but everything else is dead. Now it gets weird! If i let the car sit for a few hours i can put the key in and my lights and buzzers are back but as soon as i turn the key it goes dead again. Anybody have any ideas?

Dirty battery cables. Remove both ends clean the terminals and cables. Make sure the Ground cable is bolted to a clean unpainted surface.

Battery is a brand new Optima red top and the cables are clean. Grounds are clean,all the original ground straps are intact and ive even added an additional ground strip for the gauges, fans etc.

Still sounds like a weak battery as Steve mentioned. I'd first try jumping the car with another vehicle and a set of booster cables. It does not sound like the ignition switch.

I have this same problem, but my electrical items do work, my Optima red top battery is about 5 months old. It seems to do this on very hot days (it was 102 yesterday when I drove to the store and parked the car, when I tried to start it after I got out of the store it would not start). My mother, who was with me, said it used to happen to her and my father years ago (same car), it used to happen to me when I first started driving the car (about 15 years ago) and a mechanic finally found some wire that was near the starter that seemed to get hot, when he replaced it, it did not happen again until yesterday, but my mother put some ice in a towel and held it to the ignition switch and I popped the hood a little so air would circulate (it was kind of breezy)and shook the cables near the starter and it started (oh yeah, a lot of praying was involved too). I would love to find out what it could be.

Lita, your problem sounds like a classic case of starter heat soak. The starter motor gets very hot from the heat of the exhaust and the built up heat in the engine compartment and seizes up until things cool down a little. There are several solutions to the problem: Get a heat sheild installed on the starter motor; get a smaller "mini" starter motor, they have more torque and take up less space, so they are farther away from the exhaust and there is more room for air to circulate around them. Get a starter booster circuit installed; this adds a relay that supplies an extra boost of power to the starter motor when you turn the key. They are available from Painless Wiring.