How do I short the starter for test
 

On Wife's 1990 2.3 190E the starter will not activate when temperature is below 40 degrees. (or so it seems)

How do I short the starter and solinoid to test them?

Battery is good. Don't know about Neutral Safety Switch but I get no activity in either neutral or park.

Also is there a way to check the wiring at a junction plug to see if current is reaching the solinoid?

Any help will be greatly appriciated.

I tapped... tap tap tap... on starter and it started. But that only happened once. May have been coincidence. I have not yet tried to tap it again.