Radiator fan inop
10-27-2022, 05:50 PM
#1
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Join Date: 12-26-2014
Location: Crestview, FL
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Radiator fan inop
When I turn on my A/C my radiator fan does not come on. 40 amp fuse is new and the relay is good, the diode is also good.. The fan is new as the old one died. I can jump the relay and the fan runs. The A/C compressor is running. The relay is getting power on two legs. Could the old fan caused a problem in my ECU? I have tried everything I know and can't fix it. Seems something is not telling the relay to energize.
10-27-2022, 08:30 PM
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10-27-2022, 09:38 PM
#8
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Join Date: 12-26-2014
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I just don't know where to go next. So a wire goes from the blower switch to the BCM and then from there to the ECU and then to the fan relay? The switches seem to be working right, the a/c light comes on normal so I assume the switches are good. Where do I go next? It was working fine until my wife took it through the car wash, then it quit. I checked the HVAC relay in the cabin fuse box and all the fuses. Looks like if I ground the green wire from the switch the fan should come on? I'll get back to my shop tomorrow afternoon or Sunday and I will start tracing wires again.
10-27-2022, 10:39 PM
#9
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I was trying to explain why my question about 220F was important. The question being is it the AC or the temperature or both that don't work.
Do you often monitor the cooling fan? How do you know it was working before the car wash?
The AC compressor will not turn on unless the blower is on, the Dark Green wire tells the computer that the blower is on. Probably not important here.
You could hot wire the cooling fan to see if it works. I suspect an error in installation.
The Dark Green wire from the ECM to the cooling fan relay turns the fan on and off It depends on several inputs.
Do you often monitor the cooling fan? How do you know it was working before the car wash?
The AC compressor will not turn on unless the blower is on, the Dark Green wire tells the computer that the blower is on. Probably not important here.
You could hot wire the cooling fan to see if it works. I suspect an error in installation.
The Dark Green wire from the ECM to the cooling fan relay turns the fan on and off It depends on several inputs.