My car has a clutch fan with a belt that also goes around the alternator and i was wondering does the fan put any stress or consuming any power from the alternator at all?
Does a clutch fan take power or no?
- Thread starter boostedtsiawd
- Start date
- Status
Yes, however so do electric fans. E fans just have the benefit of not being on all of the time when properly installed, for example when thermally switched and cruising in the highway
A thermal fan however does not usually need any electricity
A thermal fan however does not usually need any electricity
Someone told me it doesnt since it runs off a belt so it takes no power and by power i dont mean from the engine i mean from the alternator/battery.
Last edited:
A clutch-driven fan takes its power directly from the engine. How would it use electric power? It is a completely mechanical system. The fan clutch will disengage if the coolant temperature is low enough, thus reducing drag and with it fuel consumption. An electric fan takes its power indirectly, via alternator and battery, also from the engine.
but the belt of the clutch fan is shared with the alternator so doesnt it put stress on it when its running?
thing is my fan clutch is always running rather the car is cold or hot and i asked a few with the same car and they said its normal for it to be running all the time.
Don't worry about it giving your alternator any grief in the least. As long as belts are properly adjusted, there's no concern, and that's the real issue, with or without a belt driven fan.
If you've ever been stuck in a drive through for a while so it gets hot, then you re-enter traffic, your fan will be locked up and you'll sound like a school bus/ dump truck. Also you'll feel it grabbing horsepower.
Next time you've driven your car "normally", go out there after you shut it down and spin your fan by hand, it will (should) barely have any friction with its hub, in other words, basically freewheel.
The other accessories... alt and power steering, are just along for the ride. If your belt is slipping or whatever then the total load of the accessories will cause trouble at high load.
Next time you've driven your car "normally", go out there after you shut it down and spin your fan by hand, it will (should) barely have any friction with its hub, in other words, basically freewheel.
The other accessories... alt and power steering, are just along for the ride. If your belt is slipping or whatever then the total load of the accessories will cause trouble at high load.
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Originally Posted By: Kira
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Heck yeah!
These clutches are a known source of potential troubles and are often not all that easy to R&R.
I'll take an electric fan any day of the week.
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Heck yeah!
These clutches are a known source of potential troubles and are often not all that easy to R&R.
I'll take an electric fan any day of the week.
Originally Posted By: fdcg27
Originally Posted By: Kira
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Heck yeah!
These clutches are a known source of potential troubles and are often not all that easy to R&R.
I'll take an electric fan any day of the week.
Me too. And if you up size the radiator you will find the fan seldom comes on.
Originally Posted By: Kira
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Heck yeah!
These clutches are a known source of potential troubles and are often not all that easy to R&R.
I'll take an electric fan any day of the week.
Me too. And if you up size the radiator you will find the fan seldom comes on.
Originally Posted By: Kira
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Yes. It is EXTREMELY common for the viscous fluid to wear out on the fan clutches on the Jeep Cherokee (XJ) and cause the things to overheat. 9 out of 10 times, the overheating is NOT caused by anything else but the fan clutch.
What year, make, model and engine?
While we're on the subject, has anyone ever heard of one of those viscous fan couplings ever breaking or leaking out? Kira
Yes. It is EXTREMELY common for the viscous fluid to wear out on the fan clutches on the Jeep Cherokee (XJ) and cause the things to overheat. 9 out of 10 times, the overheating is NOT caused by anything else but the fan clutch.
Originally Posted By: boostedtsiawd
but the belt of the clutch fan is shared with the alternator so doesnt it put stress on it when its running?
No. The alternator generates electricity, it doesn't make things spin mechanically. The alternator is not making the fan spin, the engine is. The engine makes the alternator spin, and since the fan is connected to the alternator, the engine is making that spin too. As long as the belt is tensioned properly and is not putting any undue stress on the alternator bearing, it is not wearing the alternator out at all.
but the belt of the clutch fan is shared with the alternator so doesnt it put stress on it when its running?
No. The alternator generates electricity, it doesn't make things spin mechanically. The alternator is not making the fan spin, the engine is. The engine makes the alternator spin, and since the fan is connected to the alternator, the engine is making that spin too. As long as the belt is tensioned properly and is not putting any undue stress on the alternator bearing, it is not wearing the alternator out at all.
A properly operating viscous clutched fan should be able to come to a full stop while the engine is running. Very simple to test yourself. With the engine COLD, I.E. sitting for several hours or better yet overnight, start the engine up and use an old radiator hose (or something similar that is forgiving) and slowly apply pressure into the fan. Dont just jamb it in there, slowly apply pressure to slow the fan down to a stop. A properly operating fan will come to a complete stop. If not, your clutch is locked up which demands power from the engine and costs you mpg.
Electric fans are OK for passenger cars that never see high engine demands but they do not pull sufficient CFM for MD and HD applications. Lift the hood of any truck or construction or Ag equipment and you'll see a viscous or hyd fan. They are more capable than electric fans and quite honestly they are more reliable. When an electric fan quits, you lost all your cooling capability at low speeds. When a viscous clutch locks up, the fan simply stays spinning. There are very few instances where a mechanical fan will not be able to perform.
Electric fans are OK for passenger cars that never see high engine demands but they do not pull sufficient CFM for MD and HD applications. Lift the hood of any truck or construction or Ag equipment and you'll see a viscous or hyd fan. They are more capable than electric fans and quite honestly they are more reliable. When an electric fan quits, you lost all your cooling capability at low speeds. When a viscous clutch locks up, the fan simply stays spinning. There are very few instances where a mechanical fan will not be able to perform.
Last edited:
Originally Posted By: boostedtsiawd
thing is my fan clutch is always running rather the car is cold or hot and i asked a few with the same car and they said its normal for it to be running all the time.
It shouldn't be running when your engine is cold. The clutch may be locked up and needs replacing.
thing is my fan clutch is always running rather the car is cold or hot and i asked a few with the same car and they said its normal for it to be running all the time.
It shouldn't be running when your engine is cold. The clutch may be locked up and needs replacing.
- Status
Similar threads
