For about a month now I've observed that the viscous fan, radiator fan, does not operate at idle, even if the engine has been running for over 30 minutes in the hot sun. If I drive about for a while sometimes it will a start to run and will continue to run when parked. But if I turn the engine off and restart, the fan does not spin faster than about 1 (one) to 0 (zero) RPM.

I would've sworn it's never ran like this before so my question is, has anyone else noticed anything like this with theirs?

 

Turns out clutch's failing.

 

For future reference I've just posted a video on how to remove the fan shroud and the fluid coupling/cooling fan unit or motor as Land Rover call them. Just be careful on YouTube, there's a lot of butchery out there.

You Tube

 

New fan in and sadly even the new one's operating the same, or more accurately, not operating properly.

 

Do you have a gap IID tool? If you do then you check check to see the signal that the ecu is sending to the fan clutch.

If not. Start by checking that all the electrical connections, (there’s only one really) are clean and there isn’t any corrosion or other visible damage to the wiring loom.

There is the other thing, that the replacement fan clutch was goosed too start with. I’m assuming it was a new spare from Land Rover?

 

I use JLR's SDD. Could be the new OEM fan, though the coincidence would be awfully great to have the same behaviour.

 

My understanding is that the fan’s primary job is to cool the AC evaporator coil, and it is generally only on when the AC is running. I know in my car, with the AC off, the fan hardly ever runs. When it does run without the AC, it’s only at about 20%. But with the AC on in hot weather, it’s used quite a lot. I was monitoring the fan after bleeding the coolant and my temps were still a little high. Even at 120-130 F coolant temp, the fan was not hardly on at all. But as soon as I hit the AC, it starts kicking in. This is on the SCV6.

 

That would make sense then as indicated in my other thread, last July the AC has been operating erratically, when it blows only hot air, the fan does not spin, when it blows cold like it is supposed to, the fan is running...question is, which came first, the chicken or the egg...is the fan not running causing the AC to malfunction (what the Land Rover the said), or is there an air con issue causing the fan not to run...

 

Let the truck sit of six hours with the hood opened. I always turn off the air con system before turning off any vehicle. Started it up and the fan immediately spun up as it should despite the AC being off and the engine having cooled down. Turned on the AC and it worked as it should.

But again, this has been an intermittent issue since last July so nothing to learn here other than apparently the fan does run from cold and with AC off.

 

For some time now I have observed this "new" fan running continuously, even with AC turned off, I've also noticed that it rarely ever operates above 900 RPM, even at long idle or extremely hot days. I've had the entire AC system replaced over the past year and it's recently failed again. AC specialist believes the viscous fan is not operating as it should and is causing the AC system to overheat and fail.

Does this make sense to anyone and does anyone know what the proper commanded RPM's for the fan should be?