Last night it was running perfectly.
Today, I tried to start it and it made a click sound, then nothing.
All of the lights work. When you turn on the key, all of the proper warning lights go on and then off again.
But it won't crank.
Put it on a charger. Charger showed battery was low.
Left it a while. Tried to start it. Clicked 3 times.
Battery was made in 2017.
Bought a new battery.
Hooked XK8 up to the battery in my VDP with jumper cables, so I wouldn't lose any settings.
Installed new battery.
Nothing.
No clicks.
I tried starting it in neutral. Nothing.
Any ideas?
Any fuses to check?

 

Todd, suggest you begin at the new battery. Clean the + end and follow it to the power bank (200a copper fuses). Negative cable should be disconnected prior. Loosen each nut and re tighten them snugly. Next go to the negative and clean it thoroughly, then move to the other end and loosen it it from the body ground, clean it and re tighten it also. Should it not crank over, then your should jack up car and check the body to drive train ground at right rear of engine/tranny. Once these are all clean, you may try again. No success, next are relays. Will allow other to direct you on those steps.

 

The terminals are very clean.
I tightened them when I installed the battery.
I’m not sure if there’s anything to clean on the terminals. I’ll try the other places you mentioned.
Thank you

 

Where’s the power bank?

 

Need to remove the trim cover in the trunk area at front. Remove the spare tire cover and then unfasten the tank trim cover. the power bank is at front of spare tire well. Follow the positive cable over from battery to its connection point to the bank.

 

I re-tightened the battery cables. Made sure the negative ground was tight. Checked some fuses.
All good.
Tried it and it started right up!
I don’t know why, but I’m good with it.

 

It's probably a bad connection at the crimp on the ground "strap" at the battery. I happened to me. I replaced it with a solid cable. No problems since. Cheap fix.

 

Where did you get the solid cable? You mean the negative cable that goes from the battery to the body in the trunk?

 

After replacing the battery, it still didn't start. Then, after checking the battery cables and making sure they were tight (they were), it just started. I drove it around and it seemed fine. Yesterday morning, I started it just fine, but I decided to drive the VDP to church to be safe. This morning, I went to start it and it wouldn't start. All of the bells and lights come on when I turn the key. I hear the fuel pump cycle. I turn the key and nothing. Then, after I release the key, I hear a couple or three clicks from the engine bay.
Also, when the system does it's check, I get a warning message "Cruise Not Available".
Please HELP!!

 

Make certain the gearshift lever is solidly in Park, then attempt to start the engine....

If it still will not start, shift the lever to Neutral and try again....

 

Nothing. In Park, firmly in park. I can hear the lockout release when I press the brake pedal.
In Neutral, it won't start.

 

Did you actually disconnect and clean the ground strap from the back of the engine to the chassis, or just saw that it looked clean and tight?

 

No. Tell me where to find it and how to clean it. What cleaner do you use?

 

It's on the right side at the back of the engine. You need to get under the car to do this. Just remove it and use a wire brush to clean the cable ends and mounting area on the engine and chassis. It's often overlooked.