I suspect that the fan clutch on my '83 has locked up. With the engine off, the fan should free wheel with no resistance if you spin the blades if everything is normal, right?

 

yes ,should turn easily-should also have plenty of fan
roar at around 2000RPM and up with a locked up fan
clutch

 

Thanks. There's quite a bit of resistance when I try to spin it by hand. It certainly isn't freewheeling, I don't think. My new garage still has temporary stick on paper shades on the windows. I noticed that when I start my car near them, it literally blows the paper shades off the windows.

 

Another question. If the clutch is working normally, will the fan ever not be spinning?

 

The fan will always spin, clutch locked or not.

 

Even if the car is cold?

 

Will always spin-fan speed VS water pump speed will
vary depending on temp and RPM;inside the fan clutch
,driven by the input shaft attached to the waterpump,
is a disc with concentric grooves that fit into grooves
machined into the fan clutch body-sticky silicone fluid
between provides the coupling action-once a certain
torque level is reached,the silicone fluid"shears" and
the fan more or less freewheels.Silicone fluid is directed
into chambers in the clutch when it freewheels and is
released back to the grooved drivedisc if the thermostat
coil on the front gets above a certain temp and moves
a valve leaf.Usually the fan speed is limited to about
2000-2500 rpm-regardless of temp valve position-
due to the "shear"action of the silicone fluid.Did
discover though,if the fan is too small for a given
fan clutch,apparently the clutch will turn too fast and
the fluid can't redistribute and fan will not disengage-
noise and horspower draw will occur.
BTW when you replace the fan clutch would be good
to check waterpump hub runout-have found some of
those,even factory original with runout(wobble)of
the hub.

 

But it should be turning slower if the clutch is NOT engaged, right?

 

Yep,it will be turning a few hundred RPM once silicone
fluid film shears and clutch disengages.

 

So bottom line, if you can't EASILY freewheel the fan with the engine off, the clutch is locked up and needs replacement.

 

Yes-should be able to easily turn it with a finger,hood
was up on mine and i could easily turn the fan-got a
H/D "cop"fan clutch on mine too,has a little more
turning resistance than the stock fan clutch.

 

It turns with one finger, but it doesn't spin.

 

that sounds like the fan clutch is probably okAnother test is to when starting the car after it has sat
engine off for a bit,observe if after starting up you get
a little fan roar and strong air flow that subsides a bit
after engine has been held at about 1500-2000 RPM
and fan clutch disengages.If the fan clutch bearing is in
bad shape,besides roughness,you may notice silicone
fluid leakage around the input shaft or a popped-out
bearing seal.

 

So what is that resistance from? The water pump? On my electric fan cars, the fan blades easily spin with one finger. No silicone leaks, BTW.

 

it's the silicone fluid that causes the slight resistance to
hand-turning,i have seen old clutch fans turned into
yard windmills by drilling a hole in the clutch and
draining out the silicone fluid so the fan freely spins in
the breeze Electic fans should always spin very easy
as there is only the magnets providing just a little
turning resistance-i have a GM fan motor on my oil
cooler fan and after turning the car off with that fan
running you can hear a little"rrrrr"from the cogging
effect of the magnets

 

So I guess all is working normally.

 

would you by any chance know if the 1990 irocz 3.8 5.0 has a fan clutch and if it was bad could this cause the car to over heat

 

No mechanical fans in 1990, everything was electric.

 

aw ok thank because im probly gonna change the water pump and the radiator and when i was looking up the water pump i was gonna put on the car it said would be a good time to change the fan clutch if it had one so i didnt know if it did or not so thanks again