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So my swap is finally in. I'm doing everything myself. I converted the wiring harness using xproductions diy. The swap is about 90% there. I have a few more things to do. One thing i have been wondering about is the radiator fan switch. I'm using a rsx radiator that has the switch on the bottom. my d17 had wiring for the switch on the engine harness. the k20a2 does not.... or does it and i am just not looking hard enough lol.
the engine and radiator/condensor is installed so there isnt alot of room to look around. If it isn't on the k20's engine harness. how do i wire it in?
 

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lol thanks for directing me there. it looks like i don't need to wire it up if i'm running kpro. and i am :cool: one mor little thing off of my list nice :up:
 

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I'm talking to myself here, but in case it helps anyone doing a K20A swap into an EM2. I wanted to point out that the information about wiring the fan switch is in the following post:

This is if you dont have k-pro

http://www.k20a.org/forum/showthread.php?t=49036&page=4

cranny points out that the switch needs to be wired underneath the under hood fuse box into the rad fan control relay "green/white" wire. This is the green wire with the white stripe going into the fuse box. The other wire on the rad fan switch goes to ground.

Note: there are several white wires with green stripes too, however the rad fan relay is the only green wire with white stripe on the back of the fuse box.

For completeness I have posted a diagram from the EM2 manual to explicitly state which plug its on.

http://www.k20a.org/forum/showthread.php?p=1814878#post1814878

I'm posting this in several threads so people don't have to go hunting for the info.
 

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What about if you do have K-Pro and the radiator fan still doesn't come on? I've had a K20A swap in my EM2 since 2007 and I only noticed overheating issues when I was stuck in traffic in the summer. I thought the issue was resolved when I had the car tuned because this no longer happened, but it turns out my tune file was corrupted and when I recently uploaded it again, a few issues were fixed and the fan problem returned. I just had a shop check it out today. They say that the fans work when they get power, and the problem is with the ECU because the ECU thinks the fans are on but they aren't. I don't really know what could be causing this issue. Any ideas what could be the problem here? Thanks
 

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have you tried to lower the temp on kpro for the fan? i had to lower the temp to 180 (if i remember correctly) for the fan to turn on... just a thought :up:
 

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i have the hot/cold temp set to 141, i just lowered the force radiator fan to 180 (it was at 185). I'll upload that and see how that works now. Thank you.
 

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That solved it, thanks man. just wondering, about what temperature should it be running at? its still been steadily going up and it's at 195 now. I have the overheat temp set to 220. That sound about right?
 

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Sorry to bring back an old thread but im having a bit of trouble understanding all of this, maybe im just thinking too hard.

I cant afford kpro right now either so i chopped the plug for the fan switch off the d17 harness, then i grounded the black wire and i took the green wire and tapped it into the GRN/WHT wire under the fuse box.

My car had AC but since the swap i dont anymore, i didnt hook up any of the pipes or anything either if that makes a difference.

My questions are,

Will just tapping the GRN wire from the switch into the GRN/WHT wire under the fuse box work?

Do i need to take the GRN/WHT wire out of the clip that goes into the fuse box and hook it up to the GRN wire from the switch?

When i look at the wiring diagrams from the manuals it looks to me like if i just use the tap and hook into the GRN/WHT wire right under the fuse box that should work, but i have yet to ever see or hear my fans kick on.

Im wondering if i do have it wired if possibly i have a bad relay or something, the car has 223k miles on the body.
 

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Dijinnie,

Some things I can point out:

(1) If you take the green/white coming out of the clip (which is connected to the relay) in the under hood fuse box, and ground it, the fans should come on. This is a quick way to test if the relay/fans are working. If the fans come on when you ground the wire, then you know the relay and fans work. Basically the fanswitch turns into a short when it gets hot enough essentially connecting the green/white to ground.

(2) If the fans are not coming on, you will certainly see overheating/temp issues.

(3) If you did not connect the AC tubes from compressor to condenser and reservoir, you will not have AC.
 

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Dijinnie,

Some things I can point out:

(1) If you take the green/white coming out of the clip (which is connected to the relay) in the under hood fuse box, and ground it, the fans should come on. This is a quick way to test if the relay/fans are working. If the fans come on when you ground the wire, then you know the relay and fans work. Basically the fanswitch turns into a short when it gets hot enough essentially connecting the green/white to ground.

(2) If the fans are not coming on, you will certainly see overheating/temp issues.

(3) If you did not connect the AC tubes from compressor to condenser and reservoir, you will not have AC.
2 and 3 i know, but forgive me for being dumb but which side of the green/white wire do i ground?

Do i seperate it from the clip all together or should i leave one end in the clip and cut the other end? Thats where im getting confused at this point.
 

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Leave the clip plugged in, and cut green/white.

Wire your switch to the side coming out of the clip, and tape off the other end.

Before you wire your switch (for testing), just ground the side coming out from the clip, and the fans should come on.

In terms of circuits:

Basically the rad fan switch is like a resistor with infinite resistance (open circuit) when below a critical temperature. When the switch heats up it essentially becomes a short circuit taking green/white to ground in turn activating the relay and turning on the fans.
 

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Leave the clip plugged in, and cut green/white.

Wire your switch to the side coming out of the clip, and tape off the other end.

Before you wire your switch (for testing), just ground the side coming out from the clip, and the fans should come on.

In terms of circuits:

Basically the rad fan switch is like a resistor with infinite resistance (open circuit) when below a critical temperature. When the switch heats up it essentially becomes a short circuit taking green/white to ground in turn activating the relay and turning on the fans.
Awesome thats exactly what i needed to know, thanks!
 

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i do have 1 more question before i chop into things.

Here's the fan switch diagram from the em2 manual



Do i need to follow the GRN/WHT wire from the fuse box to where it splits off and goes to the ECM and cut it after that point?

Or can i cut it before that point?
 

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I did it before @ green/white, as long at the switch is wired from the relay to ground your fans should come on @ a certain temp.

I think the point of confusion you have is the signal going to the ECU.

I honestly don't remember tying that back in, I think I just taped it off, but don't remember. (For clarification i'm talking about other end of the green/white when I cut it - meaning the side not connected to the clip/relay), however it wouldn't hurt to wire that back in so the ECU can measure it.
 

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Bringing back and old topic.

I did a K24 swap in my EM2. Well, after the first start up I had to deal with some minor things. One of them is the wiring of the fan switch.

Ive placed the fan switch in the EP3 rad and disconnected the green/white wire from the fuse box and directly to the green wire coming from the fan switch. The other black wire is grounded.

I've tried several things but the fan just wont come on. Help is wanted!




 

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Hey Baz, checkout my other post on this:

http://www.k20a.org/forum/showthread.php?p=1814878#post1814878

I have posted a diagram that shows the clip you need to work with. All you need to do to test it is take the green_wire_with_white_stripe coming out of the clip and put it to ground and the fan should come on. If it doesn't come on, the relay this wire is connected to (int the fuse box) might be dead.
 

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Hey Baz, checkout my other post on this:

http://www.k20a.org/forum/showthread.php?p=1814878#post1814878

I have posted a diagram that shows the clip you need to work with. All you need to do to test it is take the green_wire_with_white_stripe coming out of the clip and put it to ground and the fan should come on. If it doesn't come on, the relay this wire is connected to (int the fuse box) might be dead.
Great thanks! Allright, so I leave the U]green_wire_with_white_stripe[/U] in the connector that is connected to the relay? Or do i take it out of the connector?
 
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