Hi guys have not posted a new problem lately as all has been well but have an problem that has just shown its ugly head and need help bad.. Ok my 81 i sall of a sudden electrically dead..It has once or twice before intermitently (I know I spelled that wrong !) just shut down, even while running !! then crank back up no problem, now its totally dead, battery is good tested it, I crawlwd under the car and removed the main ground lead from the frame and took my dremel and cleaned the frame sufrace as well as the eylets,bolt etc, no improvment, looked everywhere for a loose connection nothing.. what it will do is when you trun the key forward to get power everything will come on, then when you turn the next click to start it everything shuts off and might stay off or dead 10 minutes or so then all the power will come back, i know this becouse my radar detector of course is in the lighter socket that is always hot and it will just pop back on, which sounds like a bad relay somwhere, (my problem is where) is the thing and does that sound like the problem or could it be a ground problem, maybe an ignition switch, somebody help !! Im in need... I have alway received great advice from you guys so Im confident that I will get the help I need... Thanks Vetttehead1963

I've had that happen before, it was nothing more than a bad or corroded battery connection.
Another place to look is at the starter, sometimes a lead will get in contact with the exhaust, that will certainly shut everything down!
There is a main ground from the frame to the block up front and one from the battery to the frame, check both.
It's bound to be something fairly simple to cause a complete shut down.

OK I have checked the battery connections good removed them and cleaned and re-connected, they are good, I will check the connection on the front and make sure it is clean, it almost sounds like a relay of some kind becouse it acts like it resets itself, I can turn the key on and everything comes alive dash warning lights lighter socket etc but as soon as I say turn on the headlights POOF it shorts itself out and can cycle the key switch and nothing !!! but just wait 5 or 10 minutes and everything will come back, but again if I try to start it or turn the lights on POOF power gone again, I have good power to the starter, I have taken a screwdriver and shorted it and beleive me there is power there big time, enough to cook you, I just dont have a wiring diagram as of yet..

I had a Ford Excursion at the shop do that to me a few months ago. I found that the Positive battery cable that connects to the starter had some corrosion in end. Even found that the corrosion worked it's way up under the insulation. I would take a good hard look at the battery cables.
On GM cars, sometimes corrosion is hidden well under the plastic that wraps around the terminal ends that connect to the battery. If there was a lot of white flakey junk on the terminal ends, chances could be that the corrosion worked it way into the cable. Let us know how you make out.
Sarge

Don't overlook the battery itself. They can have a bad contact inside the battery and cause this exact problem. I have seen it several times, but it is somewhat rare. Use a volt meter or test light acrosst the battery terminals, and try to start the car, if everything goes dead, and there is no power across the battery terminals, replace the battery. If there is power across the terminals, you have a bad connection somewhere. Don't forget to check the negative cable. And check both ends of each cable.

Ok guys I will do just that, seems odd that it would run the radio etc but who knows stranger things have happened to me as well I will keep you guys posted on my progress and will continue to try and breath life back into my beautiful Silver/Charcoal 81 Thanks Vettehead1963

A radio doesn't draw the serious amperage that a starter does. What I mean is a bad connection or battery (as Ken had mentioned) can at times support a small load. But try to push or draw a big load...forget it. Then at times after several minutes the sytem recoups itself slightly. Sounds weird, but thats the way it goes sometimes. Here's a analogy for you.
Try to picture water flowing through a say...2" pipe, then picture the pipe gets choked down to say...1/2" along the way. The water will still flow, but at a greatly reduced rate. It takes awhile for the normal amount to get through, versus no restriction. This is similar to how electricity flows through a bad connection or a bad battery. Hope this helps and is not to confusing.
Sarge

OK battery has been eliminated as a possibly problem I swapped batteries from my daily driver, to the vette and same problem as well as vica versa vette battery starts the other car just fine, so has to be somewhere else as I mentioned earlier I have already throughly cleaned the ground at the rear axle under the batter compartment, and not sure if I mentioned this or not but have excellent juice at the starter, I can short it and plenty of juice there...

I remember that there are some relays that prevent the car from starting - but I can't remember where they are. maybe one of the guru's will know. I think that one of them is a neutral switch on your tranny. I forget where the other one is. These could cause the car not to start if they were bad. (I think).

if the car is a stick... check the clutch switch.

the wires could be loose.. the switch could be broke...

or the switch may be mounted loose...

have you checked the solenoid??