Finally warmed up outside again, so set up to go for a drive in my 74. Turned key on, fuel pump started, turned key further to start engine, got a brief click, then total silence. No pump, then tried lights, nothing electrical works at all. Battery checked and is good, fuses look good, wiring seems unchanged from good condition. After a few minutes, lights were available again; so turned key, all died again. This happened twice more; now nothing at all. Took off air cleaner; all looks well at starter. Any ideas?