good points guys
I figured that since it wasn't a mechanical failure of the core that it had to be electrolysis
I don't want to re engineer the truck just see if grounding the parts will help

I don't see that grounding them will hurt since they are connected by a weak connection ( the coolant ) already. It seems to me that bonding them will help.
I'm a marine engineer and we bond everything to ground or else

Thanks for your views

hank