Electric Fan Question

[BigBlue]

Quick question yall. I installed an electric fan on the truck. It's a Derale 18" electric fan and flows 2800 or so CFM. I've got an adjustable thermostat on it. The probe is inside the upper radiator hose (I took the radiator hose off, slid the probe, and put the radiator hose back on). The adjustable thermostat is a Flex a lite version (it was a recommended part by Summit Racing). We also installed a 180 degree thermostat. The truck runs cool now. A full 1/4" tick mark below 210. My question is this. While driving, the temp stay low and the fan runs. When I stop and turn the truck off, the fan keeps running and the temp goes up to almost 210. I've adjusted the thermostat up some but it still runs. I plan on having it controlled by the PCM later, but not right now. Why is the fan continuing to run? How long should it run after the truck is cooled off? Thanks a bunch for the help.

[RedHeartbeat]

I am not familiar with a sensor that you are supposed to put in the radiator hose. Is that where the instructions said to install the sensor? It seems odd to actually put in in the hose. All I have seen are either shoved in between the fins in the radiator or wired into an engine block mounted sensor.

Could you possibly have the fan turning the wrong direction? Reversed polarity will push air through the radiator instead of pulling it through. If the controller is not powered by a switch controlled wire the fan will run until the water is cool according to your temp setting. You could have one relay running power to the other so that the fans only have power when the key switch is on if you are worried about it draining the battery when the engine isn't running. This is only needed if you are using the Bosch type relay. I had a GrandAm that would run the fans after the engine shut down and would not shut off until the water temp came down. When you shut the engine off, heat soak starts and all the heat from the block boils the water for a while and that will raise the water temp. If the fan controller isn't key switch controlled, the fans should run until the water temp subsides.

[BigBlue]

The temp probe is where the instructions said to put it. I'll try hooking it up to a switched source. Thanks for the tip. The fan is hooked up the right way. It is pulling air through the radiator and I have the wire's hooked up correctly (oddly, the black is the positive wire and the blue was negative. Said so in the instructions of the fan).

[pewter99]

Did you take the clutch fan off and are running only the electric fan? If so, was there any noticiable performance gains with the clutch fan off?

[GMCwantsLS1]

Anytime you shut off the engine the water flow stops and the stagnet coolant continues to remove the heat from the block, raising the temperature. This is normal. You probally should switch off the fan with the ignition since you will only contimue to cool the coolant in the radiator and not the coolant in the engine block.

[BigBlue]

Above 2000 rpm's, you can really tell a difference with the electric fan. The clutch fan is completely gone (that sucker was heavier than I thought). The coolant temp while driving stays at 180* and no matter what we do, it won't move at all. Any of yall know off the top of your head an ignition wire I could splice into to run this thing? Thanks a lot.

[kinjo1977]

you lifted a 4.3L????
What possessed you to do that?
Poor little engine.

[BigBlue]

That's why were installing the performance parts. The lift really has nothing to do with the power or anything. The truck performs just the same after the lift as it did before the lift. Gas mileage is still the same as well. The 31" tires were on there before the lift. Mileage has actually gone up now that the fan is on there.