90 LeBaron Intermittent Complete Electrical Failure on Startup

This just happened twice today - no prior warning. On turning key, instr lights show, but when go to start, there is a "clunk" and *all* power goes off (even wipes the radio settings). I open the door and the power comes back on. Car starts normally. I shut down 3 minutes later (after checking under the hood to see if anything looks loose or is sparking, etc. - all normal looking).
Try to start again. No "clunk" but also no power. Opening door has no effect - I think that was a coincidence. Try a few more times to turn the key and and the third try I get instr lights and the car starts normally. I run an errand, leaving car running for 20 minutes. Come back and shut down.
Is there a master relay or control module that would allow such a total failure? Is it possibly the ign switch? I saw no check light when the car was running.
Thanks!
Reply to
FredLebaron
Sounds like corroded battery terminals (posts/clamps) to me, but there are also 2 big inline connectors on the battery positive wires, one goes to the alternator and the other feeds power to the whole car.
Reply to
Daniel who wants to know

first check is battery thermals for corrosion.
Second is an intermittent loss of the heavy ground to the starter/engine block. To test take a decent set of jump cables and jump from the negative term of the battery to the engine block. If that works you've lost your engine block ground. Two option case down the cable to the starter or simply jump from the negative term to the engine block. I did this with one of my daughter's friends PU 10 years back and it's still ticking.
Reply to
NotMe

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