1993 prelude rad fan issue need help!

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We have a neat little problem with an 93 Prelude 2.2 swap The cooling fan
(passamger side of radiator) does not cycle on when engine is running at about 3/4 temp. as i think it should ....however it will come on and stay on when engine and key is shut off. (engine hot) While fan is running with engine & key off....turning the
key to the ON position turns the fan off. the fan wil run for up to an hour sometimes.
DOES ANY ONE KNOW WHAT WRONG?:confused::confused::confused:
 
check and make sure the temp sensor is good, the fan should come on wile running after its driven for a little bit
 
It is actually normal for the fan to come on when the key is off.. the prelude and accord both did that for a number of years. My 88 Prelude does the same thing, and turning the key back to the 'on' position bypasses the fan controller and it turns off. It's some kind of extra cooling feature where when the coolant temp rises after sitting for awhile it will kick the fans on to keep the temp down.

It sounds like you might have a bad fan switch though because it should be coming on when the car gets hot while it is running. If the fans are coming on immediately after turning off the car then the coolant temp is already high enough that it should have kicked the fans on. There are different sensors that control the fans depending on if the car is on or off. If there is a temp sensor in the bottom tank of your radiator that should be the one that is bad, but don't quote me on that. That's where it is located on my 88 Lude.. I had the exact same problem that you did until I fixed the fan switch.

We have a neat little problem with an 93 Prelude 2.2 swap The cooling fan
(passamger side of radiator) does not cycle on when engine is running at about 3/4 temp. as i think it should ....however it will come on and stay on when engine and key is shut off. (engine hot) While fan is running with engine & key off....turning the
key to the ON position turns the fan off. the fan wil run for up to an hour sometimes.
DOES ANY ONE KNOW WHAT WRONG?:confused::confused::confused:
 
the 93 prelude doesn't have the fan switch in that spot
i'll should probally say how the problem came about, then maybe some one knows whats doing on.

also to add to the problem (even if you just turn the key forward to turn on but don't start and turn back the ran fan will come on.

i have a 1993 si prelude
that i swapped in an usdm h22a1 wiring harness and put in a jdm h22a engine both where obd1.
i have read about an usdm h22a1 having a sensor on the elbow of where the top rad hose connects
to but on the engine i have there is no such sensor.
since i have an usdm wiring harness.

does any one know is this what could be causing my problem and how to go about fixing this
 
changed fan switch on thermostate housing and changed ECT
didn't help
has to be something with the fan switch i don't have on the elbow
need help to wire one in.
 
yes # 16 on that diagram
the main harnness is the usdm
the engine harness is the jdm
everything else work perfect but this.
maybe i already looked at it if its the one in the underhood fuse box, but where is the radiator fan timer relay located? relayhttp://images.andale.com/f2/108/108/18937703/1157986704067_1156697125638_IMG_0019.JPG
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That #16 sensor is the one that controls your fans while the engine is running, so that explains why your fan isn't coming on until you turn the engine off. So, just to clarify my thoughts, you have both the sensor on the thermostat housing and a spot for the one on the front waterneck? The JDM engine harness might not have both fan switch plugs, but I can't verify that I have always used US harnesses on all the H22 swaps I've done. Any chance you still have a USDM engine harness to check and see if there is an extra fan switch connector?

The fan relay should be located behind the glove box..
 
on the jdm harness there's an extra plug right by the injectors that if you leave it plugged up the fans will come on when you turn the key off. don't ask me why I don't know, but mine does that same exact thing if I plug that thing in. it's not on the usdm harness. it's a vacuum thing that goes between the fpr and the intake manifold. take that little valve out and plug the fpr directly into the manifold and that fan thing will stop
 
ya thats exactly what it was, it took me awhile to come across that.
although when i unpluged it, the fans still didn't come on at all.
so i wired it to a switch
is this what you did
 
my fans worked like they were supposed to with that thing unplugged. you may have something else messed up somewhere. I'm about to take an h23 harness and do away with that thing. besides my car is down right now anyways, doin an h23/vtec
 
We have a neat little problem with an 93 Prelude 2.2 swap The cooling fan
(passamger side of radiator) does not cycle on when engine is running at about 3/4 temp. as i think it should ....however it will come on and stay on when engine and key is shut off. (engine hot) While fan is running with engine & key off....turning the
key to the ON position turns the fan off. the fan wil run for up to an hour sometimes.
DOES ANY ONE KNOW WHAT WRONG?:confused::confused::confused:
 
I have same problem. What the hell.if I idle for 10 minutes the gauge pegs out.boil over.runs cool when driving as fresh air is pushed in.key off and fan runs and cools. Does anyone know why and how to fix it.at my wit's end..
 
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