lose ALL electric, 1980 LS automatic, stock
 

With the ignition switch in the ON position everything seems to work. When I turn my key to START, I completely lose electricity to everything. When I return the key to ON, still no electrics. If I go back to OFF, the whole thing repeats. Battery load tests good, battery cables good and connections sold and clean. My guess is the plastic module at the end of the ignition switch. I haven't tried battery positive to the "S" terminal on the starter yet. I need to work outside, and it snowed today. I've also searched online for at least 7 hours. I've found similar problems, but not the exact. When it warms up, I'll try various solutions, unless someone can make a suggestion.

What's your battery voltage (measured across the battery terminals) do when you switch to on, then to start, the back to on, then off?

(PS if you don't have a sealed battery, check the acid levels if you know how to do so safely. Bet they are very low)

Yeah you need to try a direct jump to see if its somewhere up in the harness. I wouldn't be
surprised if its your ignition switch as you've surmised.

Could be the switch contacts sticking/failing to close, could be a battery with very low ampacity that can't withstand the load of start condition.

Always stays at 12.84 volts. I've also had the battery load tested at two FLAPS.
Thanks, Tony Hansen

I'm going to try that on Sunday if my family isn't too busy with Mother's Day functions.
Thanks, Tony Hansen

If it is the switch, what is the best way to install a temporary push button starter switch? I do have a shop manual and wiring diagrams; but if anyone has done this, some tips may help.
Thank you, Tony Hansen

Why not just order a new switch? They are a little pricy at a little over $100 new, but still available and relatively simple to install. I've had one fail for no apparent reason and ever since have kept one in my personal "inventory" of spare parts just in case.

so, you have a 1980 Leather Sport that's automatic?

^ .. and how many folks said I didn't know what I was talking about when I said there were some autos...

Neal.

i've never personally seen one but i have heard that they exist

A couple pictures of both the interior and exterior could prove pivotal here.....

^^^agreed. pics of said unicorn LS are vital