This weekend I pulled the #42 relay and my coolant light still blinked,
making me think it was indeed the relay at fault. After removing and
replacing, it worked perfectly--once. Then it blinked for maybe 10
seconds, Then a minutes. So, all this points further to the relay.

I realized today that there is one in my diesel, but I don't know where
it it. It's in the dash somewhere, but what's the easiest way to get to
it?

Jim