Develop the tech skills you need for work and life. It will also set a code if the fan clutch is not running at the set RPM - too slow or too fast. adobe:docid:photoshop:2ce534b1-d8a3-11d8-a54e-a63691f3af4c I just repaired a electro viscous clutch today on my 02 TrailBlazer. The engine temp reads a little low all the time, about 2-3 notches below 210. As you could imagine, trying to stop a locked fan with a rag would not be a pleasant experience. Appreciate the help. Then test the fan clutch by giving it a good push. Squeaks while doing it too. While youre at it, consider the performance and fuel economy benefits of upgrading to electric cooling fans. I keep using it as an example on how to test the fan so thought it would be prefect for this article. A noisy, constant droning noise from the fan. The "drive disc" and the "front half" share these closely spaced rings. Its important to maintain the fan clutch in your vehicle, as its responsible for testing the temperature of the air coming through the radiator and preventing the engine from overheating. I just checked, and yes the speed increase and decrease with rpm. No CEL. Some fan clutches are designed with a built-in thermometer somewhere on the instrument panel. Ed and the InTechgrity Automotive Excellence Team are approved by the American Automobile Association (AAA) for repairs and are Automotive Service Excellence (ASE) certified. Check Mechanical Integrity of Clutch With engine off, rotate fan by hand. If your fan clutch has gone bad, replace it as soon as possible to prevent engine damage. Shows the signals to and from the the fan and how the fan operates when commanded by the PCM and the scanner. This includes heavy- and medium-duty trucks, agricultural tractors, vocational and specialty vehicles. Our community has been around for many years and pride ourselves on offering unbiased, critical discussion among people of all different backgrounds. '06 Trailblazer LS, '14 Silverado LT Z71, and '17 Jeep Renegade Trailhawk, "Chance Favors The Prepared Mind" Dr. Louis Pasteur, You can't have my fish, but if you ask nicely, I'll help you catch your own. You could also put 12v+ to the white wire at the clutch (or at the relay if you can figure out which terminal it is). &\cUj If your fan clutch is not operating the way it should, it's likely due to a fluid leak or a bad thermostatic spring or valve. If not, it's defective. Viscous fan clutches are belt-driven and found on many older rear-wheel-drive passenger cars. Quick tutorial on how to refill your viscous fan clutch with proper fluid and reseal the chamber. In most cases, fan blades are designed to flex up to. I found this video by Scanner Danner where he's trying to diagnose a fan code. We had a few overheating issues at Bremer Bay Why is it overlooked? The fan clutch should be disengaged with no voltage applied. By opening and closing the fluid port valve, the PCM controls the fan speed. I just want to add another thing to check before declaring the clutch dead. Thank you! Fan clutch have a patented System Sentry, which goes about as an early cautioning fuse to alarm the administrator. No CEL. A small amount of resistance always keeps the fan spinning, but its basically free-wheeling until the fan clutch engages. Its possible to upgrade from a non-thermal clutch to a more efficient thermal model, but not the other way around. No one enjoys a vehicle or application breaking down: No one. Technical Services (UK) Ltd trading as Viscofans. For more information about how to test a fan clutch, such as other signs to look for which indicate damage, read on. How Does a Viscous Fan Clutch Work? - YouTube 2004-12-07T12:21:43-05:00 Never seems to lock up completely (or even the 90%) I tried applying 12v to the clutch directly (white wire) but there was no speed change. Usually a bad or failing fan clutch will produce a few symptoms that can alert the driver of a potential issue. A locked-in, or seized, fan clutch can cause radiator fans to fully engage at all speeds. Found loose internal connections at the harness connector on the clutch and tightened them up a bit. Throw away the ruined newspaper Rev the engine, you should notice that the fan increases speed, but not proportionally to the crank speed. As the engine speed increases, the blades of a flex fan change their angle. If loosened, the P-clamp must be re-tightened to prevent the wiring harness from slipping through the P-clamp, causing tension on the Fan Clutch wiring. Search by part number to find a replacement for your fan clutch. If your unit has one, keep an eye on the temperature so youll know about when the fan speed should begin ramping up. The fan clutch won't dis engage. It will cost somewhere between $150-300 to have a new fan clutch installed, on average. (The previous clutch had loose bearings.) You should be able to hear it from where you're sitting inside the cabin of the vehicle. Company No. ELK\KHA(gYIm|eTjQ Gb$cqla7?Nf$77X!ry~1h1,amo 2jI&zI? Z;:QJ-uvgMq4Z(*n *ER"Mvz. These fans are needed at slow speeds, typically below 35 mph and at idle. 1 LEARN MORE >>, Cold-Start Disengagement helps engines warm up faster in the cold. When a fan clutch seizes, the engine is put at considerable risk from overheating, or over-cooling, and the damage done can be catastrophic if left alone. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/42\/Test-a-Fan-Clutch-Step-1.jpg\/v4-460px-Test-a-Fan-Clutch-Step-1.jpg","bigUrl":"\/images\/thumb\/4\/42\/Test-a-Fan-Clutch-Step-1.jpg\/aid9382520-v4-728px-Test-a-Fan-Clutch-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"