2008 Mini Cooper s help

For 10 weeks I’ve had tons of issues with my cooling system. It’s been to
three mechanics, the one that screwed up my car and started the whole mess
and then two to try to fix it. Codes keep going off and now my cooling fan
runs non-stop when I drive it. Thursday it puttered forever and wouldn’t turn
over. The latest mechanic said their is a faulty ground wire somewhere in the
car. He wants $75 an hour to search for it and he said it could take an hour or
a couple days to find it. At this point it’s too much money. I Don’t know what
to do. If I remove the battery is it safe to spray the engine down with water or
a cleaning chemical? It had coolant sprayed all over when my radiator got
three holes in it after it was pressure checked. I just can’t reach all the nooks
and crannies where all the wires were saturated... please help.