here is a pic of charging bay


pic of battery. I circled the fuse that gets hot when I charge it


I am going to just wait until my boat guy is available. he just had surgery

A fuse/fuseholder (if it is one) should not get hot while charging a battery. If it does, that's bad/wrong, and indicates resistance in the connection. (Heat is only generated when there is resistance expected in good copper wire of sufficient gauge). Have you confirmed that's a fuse holder? Removed the fuse to inspect it for corrosion (which can cause heat)? Is the wire connected there damaged in any way?

I can't tell for sure if your "charging bay" (charger?) has three sets of wires (AC plug, battery 1 output, battery 2 output). If there are 3 cables on it, trace them. One set should go to each battery, and one to an AC plug. Don't cut/splice wires to reach the TM battery in the front - it doesn't belong there. Move it to the rear again, making sure a red/black pair from the charger go to each battery.

I am just going to wait for Boat Whisper to get better after surgery. I am not good at this stuff.The boat is still usable. but something is definitely not right.Thx for all the replies everyone

It won't be usable for long unless you are charging both batteries.

I may be bank fishing for awhile

As it turns out the charger I had was a 2 bank charger. someone had cut the positive wire about half way. Now I know what that odd black wire went to.
But I had already bought a new charger. I got it installed. The new battery installed and it is all charging..I also got the trolling motor connected in the rear where it should be.
The only thing I have on the cranking battery are the main cables and one of the charging banks.

It sounds like you are on the path of having a trouble free system. However, anything for the boat such as depthfinder, pumps, etc. should be connected to the "main" (starting) battery. The trolling motor battery should ONLY have the trolling motor (and one charger bank) attached. You may have gotten this suggestion on connection backwards as to what load goes where. Just remember to charge the batteries when you return from a trip, not days later. Also, check the electrolyte level every 2-3 months (should be frequently enough). Note that "full to the top" is not the proper level. There's a recessed neck for each cell; if the electrolyte is touching that, it's fine. (Use only distilled water, a small amount at a time. The sooner discharged batteries are recharged, the better - they will give you a longer service life that way as they do not do well sitting in a discharged state. The cut lead on the old charger could be repaired, btw, so I hope you didn't simply toss it. If nothing else, it's a backup.

I should also mention you should check both batteries now. New ones are rarely at the proper electrolyte level when purchased. They are shipped low to reduce spillage.

Thx for everything. I will get some distilled water and keep an eye on the level. I was going to keep the old one for a backup

Thx everyone that replied.I think I have it squared away..