Radiator fan won't turn off + no A/C...

[GreekGod]

I had a problem late last fall - my radiator fan wouldn't quit running. Cool enough I wasn't concerned, so I just unplugged it. I forgot about it until today.

I was letting the car idle, and it got to 220F degrees. When I got going, the air conditioning wasn't working, but the temp came down with air getting through the radiator. After I had lunch, it had cooled down, so I plugged the fan back in, and it immediately started running. I started the car, and the A/C was back working.

I'm thinking it might be a bad fan relay, temperature sensor, or fan control CPU/module? Any ideas, or a test/trouble sequence?

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[fastblackmerc]

Try the relay first, but most likely it's the fan and / or controller. Your looking at replacing the entire assembly.

Just an FYI... aftermarket assemblies are prone to "thermal events".

[GreekGod]

Try the relay first, but most likely it's the fan and / or controller. Your looking at replacing the entire assembly.

Just an FYI... aftermarket assemblies are prone to "thermal events".

Thanks - I understand the "controller" comes as part of the whole fan/motor/shroud assembly - and the 50 Amp relay is under the hood, behind the battery.

I swapped out the relay, and the fan still ran - pulled the fuse, and it quit running (of course). So it must be the controller on the fan. I will order an assembly from Rock auto. I had to replace one on my 2000 Crown Victoria, and it wasn't too bad a job.

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[clmrt]

I replaced my assy with one from this site, solved the problem after troubleshooting the same way.

OEM is the way to go, lots of unhappy people with aftermarket failures. I'm sure there are a few happy ones, but you never hear from them. But you do hear from the people with scorch marks on their hoods.

[fastblackmerc]

Thanks - I understand the "controller" comes as part of the whole fan/motor/shroud assembly - and the 50 Amp relay is under the hood, behind the battery.

I swapped out the relay, and the fan still ran - pulled the fuse, and it quit running (of course). So it must be the controller on the fan. I will order an assembly from Rock auto. I had to replace one on my 2000 Crown Victoria, and it wasn't too bad a job.

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It's about a 20 minute job if you take 10 of those minutes to down a cold one.......... :D

[Zack]

This can happen from an AC sensor being bad or unplugged.....or the passenger side COT sensor being bad.

[larryo340]

This can happen from an AC sensor being bad or unplugged.....or the passenger side COT sensor being bad.

Yep, that's what happened to mine. The wire at the high pressure switch corroded causing an open circuit which in turn turned the cooling fan to constant high and the a/c clutch to shut down.