Ford Fiesta - Fiesta Heater

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Mon 3 May 2010 10:54
Ford Fiesta - Fiesta Heater - simonwright

I have a Fiesta whose heater stopped working and only blew cold air. I changed the coolant valve and now it will not switch off- blows hot all the time.

I checked the power at the valve end with the ignition on and the contol fully on and it registerd 12v, the same as when the control is in the closed position. Does this mean I now have a problem with the control unit.

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Mon 3 May 2010 19:59
Ford Fiesta - Fiesta Heater - topbloke

more than likely, the heater valve has a 12v feed and the earth is controled via the panel it is a pwm (Pulse Width Modulation earth) and you wont see the signal with a dmm or trest light the only way would be with a scope however that said the usuall culprit is the heater control unit these fail almost as much as the heater valves themselves,Regards TB

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