1993 model
engine stumbles and shakes (loss of R.P.M.s) at idle ,in gear,with A.C.on---
after medium speed (35-50mph) runs... with no aux fans operating
Ambient temps 100 degrees "F", engine temps 80 (rising to)100 degrees[+]
"C"[nowhere near redline]
1. Where is physical location of aux fan(s) resistor?
2. Could "Heat Sink" @ idle after medium speed runs without aux fans be
affecting the engine or some of it's controls in a causitive way with
the loss of R.P.M.s and "shaking"?
'have no access to either manuals or service C.D.s for 190E 2.6
'have NOT operated vehicle,belongs to friend.

Any thoughts appreciated.

Doubt it... aux fan cut-in temp is not until 105C, and low aux fan is only with a/c operation and only when a/c high side pressure is under high thermal load.

Thank You,
A.D.

So, if I understand correctly...low speed AF does not come into play until
HP SW (on R.D.) rises too far.('do not know "High" side [or "low"] pressures)
{"Navigating without Radar or G.P.S. in a fog bank @ night with blinders on"}
I mistakenly thought the fans operated whenever the A.C. was on.
I'll pull wire(s) off heat SW on engine and then jump HP SW on R.D. to see if
either one starts fans.(first check fuse for corrosion or breaks,relay for operation)

Idle + shaking problem... goo in the intake? heck I have no idea when the
filters were changed.{See above thoughts }