Adding a coolant heater on a D13000

Well my Hotstart coolant heater finally arrived for the old D13000. I am trying to figure out where to install the supply and return lines. They have a handy installation video:

https://www.youtube.com/watch?v=RxukiZsUUbM

This is the kind I have, which runs just shy of $700. Please don't mention that to my wife.

[attachment=40194]Hotstart CTM.jpg[/attachment]


So now I have to find out where to hook it in. There are a lot of port plugs at various points on the engine - is there a place to find out which ports are for the coolant? I've tried looking at the sketches in the Parts Catalog (the original is a work of art), but I haven't had any luck yet. Because the lines are so small I thought it would be best to thread a nipple into a coolant port. I'm just not sure how to tell which ports are for coolant.

Has anyone installed one of these heaters in an older D13000? It should help keep the engine room warm and dry.

Here's the boat she is in:

[attachment=40195]15940571_10207627773084020_2648959701619376574_n.jpg[/attachment]



Thanks for your ideas and suggestions - Chris

Usual connections are at the thermostat housing and the engine block drain.