Belt and Belt tensioner installed 95 Windstar 3.8L; battery light?

I have spent 7 hours taking a couple breaks, in the dark, going slow, and near 100% humidity the entire time to where the boxes in my garage are all soft. My problem has been for a while that my van will not even make an electrical connection (no ground) from the alternator to the van body over that absolute piece of crap ground wire that Ford put in there, but more over because the last time I worked in that area I could not get the alternator mounting bolt tightened all the way (had it 95% of the way) because I was trying to tighten it after the fact when the belt was putting great tension on the alternator pulley. I eventually wedged a washer in there which managed to wrap around that bolt about 75% and tighten the bolt just enough so that the washer was snug.... however over time as you could imagine this presented issues in humid and even rainy weather to where I would not even have a ground AT ALL to where I'd have ZERO dome lighting and the van would not even CLICK when I'd turn the key. All connections at the battery are fine and great and the battery is new.

The other day in the rain the condition presented itself and I was stuck in a parking lot until I could use my makeshift ground wire (the jumper cables) to ground from the engine (or van body) to the alternator and I was able to get it to catch one time to get me home, but as soon as I got home the connection was lost completely and I realized I had to go ahead and fix the rigged up ground wire deal. I had a new belt tensioner already, new belt, and putting on a different heavier gauge ground cable from another car I have. After cleaning all the connection points and even wire brushing them and putting it all back together my dome lights were back and more importantly I knew this would make the van start and hopefully now without the very bad chirping/squeaking I'd had before which made me realize with the help of someone else that it was probably the tensioner going bad which was correct. Chirping/squeaking gone, van starts in this awful near 100% humidity, and there are no non-start times.

Thinking I have the issue licked I go out and drive it around hoping to find some food at 3:20 AM and would you believe that at 3:00AM the Burger King 24 hours shuts down their systems for 20-30 minutes... this I did not know of course and tired and hungry at this hour it didn't make me too happy. Onto SUBWAY ! lol - Anyway the van drove fine the entire time with the exception of when I came home.

As I drove it home I was doing about 55mph and wanted to see how it would do gunning it for 70-80mph to see how interstate travel would be. Well I am not sure at what point (might've been during deceleration; think so) I saw it, but the battery light flashed on for a few seconds and then it just turned off on its own. The van had NOT tried to stall and seemed to be running fine, but of course this last "gunning it" motion was my final test before I pulled into home to see if everything was good to go and then I see that damn light.

Could this be due to the humidity? Maybe the new belt slipped at the high rpm? I even put silicone around the connection at the alternator this time to ensure no humidity or buildup getting in between the connection point and it is as tight as I can get it. It is a good ground cable (old, but good) to my knowledge. I want to go take it on the interstate tomorrow and see if it does it again and either way I'm going to go have the battery and alternator tested just to make sure I'm good in those areas. The other things I was wondering is possibly could the van be learning new tension IE: new force/speed with the new belt and tensioner and this caused some kind of GOOF to happen? I could tell that the new tensioner was considerably more "tense" than the old one. I just found the battery light coming on at high speed (say 65 - 70mph) odd after having done the work I did.

Thoughts?

I've had troubles with the ground in my '98. Sometimes it would just shut off while driving and not start again. I made my own cables from stuff at the Advanced Auto Parts.

I notice you didn't mention the other ground wires.

The biggest is the negative battery cable. It grounds on the transmittion.

There is also a small one that goes from the negative battery terminal connector to the frame.

I've had troubles with the ground in my '98. Sometimes it would just shut off while driving and not start again. I made my own cables from stuff at the Advanced Auto Parts.

I notice you didn't mention the other ground wires.

The biggest is the negative battery cable. It grounds on the transmittion.

There is also a small one that goes from the negative battery terminal connector to the frame.

Yeah i was thinking off adding more ground cables. The negative battery terminal one I believe has always seemed to be fine. I don't believe there is one grounding from the neg post to the frame though. Maybe that was in newer models? In any case the grounds in this engine bay suck and need improvement anyway.

QUESTION: COULD A SMALL BUG (MOTH) FLYING INTO THE ALTERNATOR ASSEMBLY CAUSE THE ALTERNATOR TO BREAK?

This has happened while I was working on it and I was wondering maybe the damn bug flew in the wrong place in the alternator and broke it.

Nobody has any other comments? I guess that means I've got it all figured out...... or does it? lol

Well looks like I answered my own question. With the ground wire being in that kind of "shorted" state with the humidity between it and the alternator mounting bolt point power was intermittently trying to get through the van's wiring as it sat for a couple days and probably on other humid days as well when I didn't realize it. As a result this over time (in sort of an on off on off on off type of phase) drained my battery a certain amount. Took it to Autozone today and had the battery tested and it said "Charge and Retest". I charged it last night and will bring to Autozone in the morning for another test and then will test the alternator too at that point.