So putting parts together for the IC, the radiator from a 1980s VW Scirocco has a 22mm size hole, which is little over 1/2" in size where a cooling fan switch screws into.
Well looking all over town, couldn't find anything to plug it with.
I ended up ordering a switch which will not be used, LOL!
http://www.germanautoparts.com/Volkswagen/Scirocco/Cooling/208/1

Autozone wanted $26.99+tax

Top right corner is where you see the hole.

I picked it up for $12.69 shipped.

If anyone is interested in the $62 shipped fmhe of a VW Scirocco, this is some insight for you.