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Old 15th November 2019, 13:01   #21
T-Cut
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Rover75 and Mreg Corsa.

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[QUOTE=SD1too;2775726]
Quote:
I would suggest that the chart applies to the 2 speed resistor fans as well since the control software is within the ECM and it cannot "know" which type of fan is plugged in, particularly as 2 and 3 speed fans were fitted
to cars in an apparently random fashion up until the end of production.
I didn't say the ECU knows what type of fan is fitted. It's simply down to the differences in motor brush and relay wiring and is totally independent of the ECU. So, when the 2-speed replaces a 3-speed all four brushes in the motor are permanently in circuit and it runs at what might be described as 'medium' and 'high' speeds. In effect, the old low and medium duties are both provided by 'speed 1' in the new system.

Quote:
So since it's said that the 'heat soak' condition triggers the medium speed which doesn't exist on a 2 speed fan, I'd like to ask if any KV6 owners with 2 speed fans have witnessed this.
But to justify your doubt you should also ask if any KV6 3-speed owners have witnessed heat soak operation. I'd expect similar statistics since the potential for engine-off 'after boil' exists whether it has a 3-speed or a 2-speed fan. I can confirm that the MEMS/2-speed triggers heat soak cooling in the 1.8T - for up to five minutes as I recall. I note the KV6 is set for up to ten minutes, logically because of its larger thermal capacity. I don't think heat soak is covered by RAVE, the MGR diagram is from elsewhere.


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