battery/alternator fine-solenoid?

[bellyboy]

last week i thought we figured it out. cleaned up the terminals worked fine for a week. started fine on saturday drove it a half hour, sat for 20- wont started. battery/ alt seem to be fine.

all electronics work fine when it doesnt start. i ll turn the key and it wont do anything, doesnt click continuosly. no turnover. i ll do this a few times and it will start right up.

when she starts which is 90% of the time lately- she starts right up no hesitation.

your thoughts are appreciated.