Radiator fan always on

Falcon20x

Registered User
Awhile back I had what I believe was a engine overheat. I noticed the temperature gage dropping down to almost nothing, the coolant expansion tank was full with a lot of air bulbs coming up. I was expecting the water pump to have failed so I started to tear down the engine and found out that the themsotat fail safe had worked as adversidsed but instead of a bad water pump it was a sheared off head stud that caused the problem.

The fan always worked as it should until that day. Now regardless of the temperature of the engine ithe fan runs all the time. Is there a reset or something that I' m suppose to do after a overheat.

I rebuild the engine and it should be ready to go in a week or so. I really do not want to have to do this again
 
Engine off and on. Both

Might be a stuck relay in the IRCM. Do you have a spare you can test with?

Strange tho that it seemed to coincide with a major repair, tho. I'd suspect harness and/or grounds in that case.

And no, there isn't a 'reset' in your example that I know of.

Note when the ECT sensor fails (or is disconnected), it only runs the fan with key on _and_ engine running. You might disconnect it just for fun to see if anything changes.
 
The fan always running was already there before I started to tear down the engine.
May be when the sensor needs fails the computer turns get fan on?
 
The fan always running was already there before I started to tear down the engine.


Now I'm confused, because you originally said "The fan always worked as it should until that day." Always on isn't working as it should.

And yes, a failed sensor can cause the computer to run the fan, but that should only be with the engine running. Go ahead and replace it if you like, since that's easy to do and less than $20 (as opposed to finding another IRCM), I think, but keep the receipt...
 
Sorry for the confusion. The fan works as it should before the overheat, after that it was always on. I was just trying to say that the issue was there be fore the tear down.
 
Ah...after o'heat, before repair, got it, thanks.

What procedure did you use to bleed air out of the cooling system when you put it all back together?

Any idea if the fan is running at low or high speed?
 
IF its the IRCM tap forcefully (don't dent it) to see if the relay is stuck. If this is the case it can be repaired with a little soldering.
 
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