How do I check fan clutch?

[wayne2970]

I am having a problem w/ my 1992 300D
running hot.

Temp climbs while idling and afer a hard run.
Sometines to 110 degrees.

replaced cap, thermostat, and coolant, seems alittle better.

With engine @ 100-105 I can reach in and stop the fan cluch by hand w/a towel

1. whats the acceptable operating temperature range?
2. when do the aux fans come on( passenger side fan doesn't seem to come on often) ?




Wayne