Going nuts trying to fix this, radiator fan comes on when ignition is turned on. This is a 92 Geo(Corolla) with a 1.6L manual tranny. T-stat is operating like it should as the engine temp.stays right in the middle. I've pulled the coolant temp. sensor wires and it still ran. Only way to stopit was to pull the fan relay. Swapped out the fan relay with a new one, same thing, runs all the time. Any help would be great! PS- this is a new(?) car to me but surely it's not designed to do this, isi it?
Pulled sensor and cleaned the end shiney new like. Put it in a pot of boiling water(212 degrees). Checked with ohm meter before and after heating...no change(continuity, indicating a closed switch). Could this be the problem? Book says it should "open" at 194 degrees. Seems like it should"close" at 194 to turn the fan on. Still bewildered
might be that the wire that goes from the switch to the fan is broken somewhere, or doesnt get contact with the thermostatic switch. Causes the fan to run all the time.
Fan temp sensors are normally closed, continuity, check for opens in the sensor circuit, as well as a shorted fan relay. The fan sensor if memory serves me is in the lower radiator tank.
Well found the correct sensor and it does show "open"(no continuity) all the time(even after in boiling water), so I'll change it out and see if that stops the fan from running all the time. Funny thing is , I pulled the lead to the sensor and jumped it , but the fan STILL ran all the time...strange
was it the white single wire sensor? the white one, i believe, is the one that turns on/off the fan.... and is in the thermostat housing.... for the ae92, there aren't any sensors in the radiator
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1) 2004 IS300 Manual/LSD/Sportdesign 2) 2010 Corolla S 5 speed 3) 1986 MR2 "MK1.22" 5sfe/s54 swap 3) 1995 Ford Explorer 4x4, TT/AAL/custom shackle lift, 31"s
uh, there isn't supposed to be continuity when the coolant is cold.. the switch should be open. once it heats up and passes a certain temp the switch will close, grounding itself and activating the fan relay and therefore turning the fan on.
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Sure enough Toyotaspeed90, white sensor with one wire...2advanced, one would think that is the correct way the switch would work , but it doesn't , IN THIS CASE. It's a fail-safe setup so if the sensor fails , the fan runs all the time instead of never.This info. is per the repair manual, not heresay. Also,Hossy, there is no sensor in the radiator tank.
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