Starter/Ignition intermittent problem. 1993
 

My 93 has a strange intermittent problem during start up, after sitting on trickle charger for some time. Month or so..
When I take the charger off, I put key in ignition, turn to get fuel pump running, wait, then turn key. Nothing. No click, nothing. All lights come on on dash, and it loads as you can see a slight dimming of lights. But no click, nothing.
As soon as I put a set of jumper cables on and try it fires immediately, no hesitation. Then, it starts fine for rest of the day.
Going to run it today, and see if same symptoms. I had to ump start it last night to move it. Once I did, I test started it 3 times last night after idling for about 10 minutes.
Battery is about a year old, always on trickle charger. Rarely driven.
1993 Corvette, 164000 miles. Starter is about 18 years old as it was replaced in 2002 era when I put new engine in. But we are talking maybe 20000 miles since then.
Any thoughts?
Safety Switch( it will start in any gear (automatic), starter cable to solenoid loose? Ignition switch?

Sort'a sounds like a loose connection on the battery or a bad battery.

Draw or previous suggestion battery or connections. Have battery tested with digital tester.

Have battery bench tested? Or just put a meter on it.
I figured trickle charger, battery tender would keep battery good.

The battery could just be defective. Some parts stores test for free.
I went through battery roulette before getting a good one.
A trickle charger that doesn't cut itself off once battery is charged; can boil acid out of battery, causing failure.

I guess , or so I thought, battery tender jr was a solid product..

My tender has float mode. So, I may have a loose wire, if battery checks out

I came home, tightened battery. Tested it first. It was 12.3 volts. After tightening it was 12.75. Both terminals on battery were half a turn loose. Hmm.
I may take it in this weekend to an Advance or AutoZone to check if its okay. I think its years old, garaged 99% of the time and on battery tender.

.4 volts is alot particularly during start. You may have solved your problem.