'95 E300 gauge problems

[KarTek]

Guys,

After searching and browsing 14 pages of posts on "gauges" I have a couple questions:

I'm helping out with the wiring on a '95 E300. After getting the engine wiring replaced and working well, the oil pressure and temp gauges don't work. I don't have a wiring diagram so we have to visually trace everything with is a huge PITA.

So, which actual sensor is for the gauge? There are 3: one in front and two in the back of the engine.

How does the gauge panel come out?

Is there a "typical" problem with these gauges that I might look at as a start?

Thanks for the help!