So I got a 89 toyota pickup a couple days ago. it was running a bit hot because the cap was toast. so I replaced that. Started it up and the fan started right away.(this is a cold truck with 10 hours of sitting over night.)
So fan clutch isn't working right. I don't totally understand that piece so my question is.
Will something cause the fan clutch to run the fan all the time other then the fan clutch being broken? Like a sensor or something?
It runs colder now on the gauge which may be wrong I know they suck in this year range, but seems to be telling me what it feels like under the hood.
From what I have been able to find on this site I would say no, and it needs a new fan clutch or a rebuild of this one.
Am I going in the right direction? I plan to do the thermostat change next Tuesday.

 

The fan clutch always spins. Its not electrical and nothing tells it to go on or off. The clutch on the inside of the fan is filled with silicone fluid. When the fluid is cool it has low resistance so the fan doesn't spin as fast, when hot it has more resistance so the fan spins faster.

When the engine is cold (and not running) as ice spin the fan by hand and it should have little resistance. When the engine is piping hot (and not running) spin the fan by hand again, it should have much more resistance.

 

Oh I see. Then maybe it is working right. I suspect that thermostat is stuck open then. It is running somewhere between cold and normal running temp. Like maybe the needle moved half the distance it should for normal running temp. Before replacing the cap it would run at normal temp unless I was driving on a 100 degree day, with the ac on. then it would climb 3/4 the way to redline then hold there. Maybe I just have a bubble in the system. I will start with topping off the system and seeing if it will burp for me. I suspect that cap lost some fluid for me both orings where cracked and the one on the spring had like a cut out of it.

 

Ok so I went back to my truck at lunch to drive out to dmv and I tried turning the fan and it was really easy. Then I drove it too and from DMV and it actually warmed up to normal running temp and stayed their by the time I got back. Tried the fan then and it was exactly the same. Probably going to park her till tuesday when I get a chance to deal with the clutch fan. I think it is just not picking up and spinning fast enough, but I am going to remove and check the thermostat before i go buy the clutch.
So next question.
Does any fan clutch work or is this a buy at dealer only kinda' part?

 

If you get a AISIN brand (check rockauto) you are good to go. AISIN is the Toyota OEM fan clutch.

 

Ok so yesterday after driving 15 miles home and running the ac all the way lots of stop and go (over 100 outside) it only started to go over a tiny bit as I was getting home. So it seems to be running in normal temp range but I think if I put more miles with the ac on it would start to climb.
The fan was really easy to spin when it was hot. like just a small flick and it would spin 3/4 the way around.
I tried it again this morning after it had sat all night, and it was actually harder to spin. maybe 1/4 to 1/2 spin around on the same kinda flick. I know it isn't scientific but it doesn't seem to be working right at all.
Also probably start another thread about this but noticed it doesn't really idle right when the ac is on, it surges a bit.

 

If it's only going slightly over normal temp at 100deg in stop and go traffic with AC on, I don't think I'd worry too much about the fan clutch. Sounds like it's getting the job done just fine. Unfortunately, the FSM appears to be completely silent on the subject of the fan clutch, so I can't help you with official test procedures.

If it's taking a long time to warm up, then yes, that's probably a thermostat issue. Generally the engine should warm up to normal operating temperature in 5 minutes or so and then stay there.

 

okay, so changed the cap then it took for ever too heat up..
so i changed the thermostat.
so i found out the stock aisin ones are order over the net or dealer around here. i chose the option of replacing with a autozone part. i will rebuild the stock oem one and hold onto it.
runs great now acts like you would expect it too. it doesnt surge when at idle with ac on. case closed.