My daughter's 1993 180E 5 speed was a proper pain to drive with the air conditioning on.

The electromagnetic fan is wired so that when the A/c pressure builds both the electric fan and the electromagnetic fan are activated.

This means that the fan runs most of the time in summer in Australia.

The electromagnetic fan is about 18 inches in diameter and, judging by the effect on the car's performance must have consumed about 20 horsepower, not to mention the sound of a jumbo jet about to take off.

It was not too bad if the A/c temperature switch was moved about 1/4 of the way on but it ran almost 100% of time if the switch was more than 1/2 way on.

Experiments with the fan disconnected showed massive improvement in the driving pleasure and no discernible change in the A/c output. ie only electric fan running.

The system is wired so that the electric fan is not activated when the temperature of the engine is elevated so the engine would be vulnerable if the electromagnetic fan was disabled permanently.

My solution was to disconnect the electromagnetic fan at the connection just under the front of the air cleaner and "hot wire" the electric fan to the same connection.

In this way the electric fan only operates with the A/c but also operates when the engine temperature exceeds 100 degrees C.

Tests so far have proven massive improvement in driving pleasure (no howling fan or reduced performance) and the electric fan cuts in on long slow hill climbs and drops the temperature in short time.

I hope this quick fix helps others who are putting up with similar problems

Peter Cowie
Sydney
Australia