95 S420 no low speed Aux fan ? Why ?

[DanielW]

I am trying to discover why I never seem to have low fan operation, even at very high outside temps (100-105F). My air cond. is very marginal at these temps. When restarting a hot car sometime the compressor will not engage, but never does the aux fan come on unless the engine temp climbs up above 100c (example very slow traffic or idling at these high outside temps). Am I assuming that the no compressor condition is because of too much high side pressure at the dryer switch or compressor. Aren't those the conditions under which the aux fan should have come on, but does not, so instead of cooling my car interior it simply cuts off the compressor to avoid damaging it ?

Why would my condensor fan have a resistor that has 500 megohms restistance. (This is orig MB with Ohms printed on it---- part number is 000 158 4045). This seem far too high a value to have any impact on fan speed? Most other MBs of that age have a large steel wire which drops voltage from about 14v to ? 7-8v so that the slower speed Aux fan will not be as loud. Every part source I have checked shows this steel spring mounted on a ceremic block. My car has a 1/2 inch round plastic covered (black pencil like) resistor mounted very close to the front plastic grill parts between the two aux fans. They must not have thought that there would be much heat for the unit to dissipate since is is completely plastic clad and very close to the grill. FastLane and other sources show the ceremic block with metal spring for my year car. What am I missing. Is there another resistor somewhere else on my car. I have looked for one but have not found anything like what the parts illustrations show.

I have an appointment set with and independent MB Tech but would like to be better informed prior to that.

Any help or info would be appreciated.

DanielW