everytime i cross water at a higher rate of speed it seams to cause my alternater to go out i have been through 3 since i started wheeling my 86 xtra cab yota. is there anything i can do to stop this from happening evertime i go. spash shield or something like that. any ideas would help my pocket book and my knuckles from being busted changing these things in the field.

 

How about SLOW DOWN

 

Pick up an old school manual and study how to rebuild alternators. In my experience it's usually the diode that gets ruined. You can pick up diodes at any electrical hobby shop. If you have a good DVOM you can test diodes. A diode costs 5 bucks maybe. Or possibly investigate into a remote voltage regulator like old school rigs. This may not be possible however.

I might also suggest not crossing water, lol.

A patient told his doctor, "Hey Doc, it hurts when I hold my arm up in the air like this."
What do you think the doctor told the patient?

 

It is a truck, not a boat - it will never plane no matter how fast you hit the water. There is a good thread on water crossings here do do with speed & technique to not wreck your truck. I would suggest reading it:

https://www.yotatech.com/forums/f123/speed-water-74400/

good luck