Author Topic: Switch to stop fan (Read 2173 times)

barsy · « **on:** November 06, 2006, 10:31:37 PM »

Hello,

I have had my 1989 126 off the road as I seem unable to locate for sale a switch that is screwed to the fan housing and would appear to be for switching the fan off after the ignition has been turned off - currently the fan continues to run and has drained my battery!!

Anyone know where I can get this from?. I have tried Ricambio and the "parts from poland" listing but for whatever reason they have not returned my email requests.

Thanks,

Barry

Chris Lakin · « **Reply #1 on:** November 06, 2006, 10:35:05 PM »

hi Barry looks like you will have to get a second hand one

bit anoying that, as these seem to go quite often

regards

Chris

stuey · « **Reply #2 on:** November 07, 2006, 12:15:19 AM »

if all else fails just get an auto electrician to wire a relay in that cuts the power to the fan when the engine goes off... shouldnt be hard and at least the parts will be replacable off the shelf stuff...

banjomandolin · « **Reply #3 on:** November 11, 2006, 11:48:51 PM »

Hi Barry,
The "switch in the fan housing" is part of the cooling fan 2-speed control. When the thermostat in the rad senses 96-100 deg. it closes it's low speed contacts but diverts it's earth thro' the resistor (the coil of bare wire) in "the switch" which allows slow speed only. When the rad. temp. reaches 101-105 deg. the thermostat in the rad closes it's high speed contacts and another earth is directly earthed i.e., not through the resistor. and at the same time energises the solenoid adjacent to the carb. which opens up a vacuum line which allows a mechanical linkage to increase the carb. throttle opening. The resulting extra power is required to compensates for the power lost by the fan running at high speed. My bet is that one set of contacts in the rad. thermostat is sticking in the closed position resulting in permanent fan operation. Ricambio do stock these thermostats. You can test the fan operation by separating the two push in connectors adjacent to the thermostat and short out the brown and black for slow speed and the grey and black for high speed. The cooling system control arrangement is shown in the wiring diagram page 22 of the workshop manual.