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Discussion Starter · #1 ·
Hi Guys

New here. Does anyone know how does the CDi know when to switch on the cooling fan? And then also when to give you a "High Temp" Warning?

Seeing that there is no Temperature (analog) sensor used no where. Only seems to be the ECT (Engine Coolant Temp) sensor, and this seems to only give 1 signal to ground when preset temp is reached. This, I presume, is for when the fan needs to kick in. So when does the CDi decide to give an output to the Warning Lamp?

Time based maybe?

Any light on the subject would be highly appreciated.

TIA!!!
 

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Making HP ain’t free. . .
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Depending on the resistance at the ECT sensor, it will either turn on the fan or once it gets up to 248° I believe, it will trigger the temperature sensor light.
 

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Discussion Starter · #3 ·
Depending on the resistance at the ECT sensor, it will either turn on the fan or once it gets up to 248° I believe, it will trigger the temperature sensor light.
Thanks for the response. The ECT, however, is just ONE signal. Which ever temperature activates it, shorts that wire down to GROUND and that is how the signal gets sent to CDi. This ONE signal, I presume, is to start the cooling fan. So how does the Temp light then gets activated?
 

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Making HP ain’t free. . .
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Same way everything works nowadays, different ohm readings. The ICM receives a different ohm reading and either activates the fan or the light.
 

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Same way everything works nowadays, different ohm readings. The ICM receives a different ohm reading and either activates the fan or the light.
So it is an analog signal that goes back to the ICM? Okay, that would explain it.
 
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