First, I've searched multiple threads for this problem and some appear close but I have had no success.

Background- Car is driving fine, I make a quick run to gas station and come out, it won't start. Lights come on, no flickering and I get a single "click". This could be the solenoid but it was pretty loud. When I return the key from the ignition position I hear another "click" not as loud.

Attempted to jump the car, no luck. Doesn't change anything. I have it towed to the house. I get my 8mo old battery tested, it's good but around 65%. The battery was charged back to 100%. Before reinstalling, I connected the battery cables to another car leaving the battery out of the circuit, it definitely made a difference as the starter was definitely engaging with a rapid "click click click". I the reinstall the freshly charged battery and the car starts. I turn on and off twice to ensure everything is good.

At that point I leave the car overnight, attempt to restart in the morning and the car won't start, I'm back to the same problem. Any ideas?

 

With a DVM measure your battery voltage.
Check the connections to the starter.

 

Thanks,

Because I'm in a hotel, I'm limited on what I can do. However I was able to just barely squeeze under the car to get a picture of the starter. I wish I could get the car just a few more inches off the ground. I took pictures of the starter below, had some questions.





Not sure what that is on the connection between starter motor and starter, was this some kind of insulation?





Should something be attached to this spade?

 

The bolts look corroded. Disconnect battery, clean the connector & try.
PS. First make sure the battery is ok. What is the voltage in the morning?

 

It was 13.4 (ish) when they tested it last night. I replaced the battery ground tonight because it was loose and I couldn't get it tight enough. All of the terminals at the battery are clean. I was more concerned about that spade on the solenoid, it looks like something would be attached to it, is that not the case?

I'll get a wire brush and try to knock off corrosion around the starter in the morning. I may have to bite the bullet and get it towed to a shop, living at a hotel is making this much more difficult.

 

The ground being loose might be your problem. Test the battery voltage in the morning. It could be 13,4 in the evening, but it would not keep charge until morning if one of the cells is cooked. Don't worry about the spade. Disconnect battery, then remove the starter cable bolts & wire brush them........
But I would think your loose earth is the culprit.