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Rad fan swap for 1999 VFR

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I have a 1999 VFR and would like to install a rad fan blade with reverse direction of air flow.  Many discussions mention replacing  the stock fan blade with one from the VTR1000. I want to know if there is a specific VTR model year from which the fan blade fits the 1999 VFR fan motor/shaft. Is there a better alternative to the VTR blade? Information needed so I can order a suitable replacement fan blade. Help appreciated.

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If my whatchamacallit doesn't fail me, the SP1 fan is the one you want, not the SP2 one. The info is on the forum in a thread somewhere...if people used the same thread instead of opening new ones the info would all be in the one place and easy to find.

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I bought one for my 6th gen.  Somehow before getting around to installing it I put in a fan over-ride switch allowing me to turn it both on and off as well as letting it operate normally.  That worked so well that I forgot all about the idea of installing the other blade. 

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+ 1 on the above. 

I often ride in 40*C temps and have not had a problem since doing the same. 

Also keep in mind that fans do not push as much air through a radiator as they pull. 

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On 8/8/2018 at 7:27 AM, VFROZ said:

+ 1 on the above. 

I often ride in 40*C temps and have not had a problem since doing the same. 

Also keep in mind that fans do not push as much air through a radiator as they pull. 

There are two schools of thought out there about this. Yes, you're most likely correct, that a fan will pull more air through the radiator, as opposed to pushing. I suspect the equation changes somewhat when the bike is in motion, and air is being "funnelled" through the front of the bike (and by extension out through the rads).

 

To the OP, the principle behind the swap is simply to have the fan (at slowish speeds) directing air in the same direction as it enters the bike - i.e. from "inside" to "outside". The standard VFR fans is fighting against air being forced in through the front of the bike, and flowing out the sides via the rads, as it is trying to draw air from outside the bike (ostensibly cooler air) through the LHS rad and into the area in front of the engine.

 

If the bike is stationary, the stock fan is probably best. At pretty much any speed above that, the VTR blade is the way to go. (IMHO)

 

For the record, I have done the VTR(F) blade swap in my '99.

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On 8/6/2018 at 6:54 PM, Cogswell said:

I bought one for my 6th gen.  Somehow before getting around to installing it I put in a fan over-ride switch allowing me to turn it both on and off as well as letting it operate normally.  That worked so well that I forgot all about the idea of installing the other blade. 

Can  you get a pic of this? I would like to wire this before my big trip up coming. 

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I'm not sure a photo would be helpful - on my 6th gen the wiring snakes around the ABS pump and doesn't lend itself to an all in one photo. However, it is fairly straightforward to describe. 

 

First you need to decide which you want:

> Fan Normal / Fan On   - I won't cover this as I didn't wire mine this way. 

> Fan Normal / Fan Off / Fan On  - this is what I have.  This gives me full control  - normal,  off at speed, on in slow traffic. 

 

If you want the first, you need a single throw (two position) switch (off / on).  If you want the latter, you need a dual throw (three position) switch - on / off / on.  Be sure not to get a "momentary" switch.  Personally I like one that's waterproof.  A 3 position switch will have 3 connectors - I recommend the type with blade connectors as that's what Honda used on the fan circuit.  You also need to decide if you want a toggle switch or a rocker switch.  Either is fine - some of it depends upon how you wish to mount it.  I chose a rocker as I did not want to see the handle of a switch sticking up.  YMMV on that one.  At any rate, I have a round dual pole switch (dual pole meaning with two parallel circuits), making it a "dual pole dual throw" (DPDT) switch.  In the case of the dual pole switch, it will have two parallel sets of blades, 3 in a row by 2 sets.  In this application one set goes unused.  I got mine from Cherry Electric - similar to this one.

 

https://www.amazon.com/Rigid-Industries-40181-3-Position-Cherry/dp/B00O3HDA26/ref=pd_rhf_se_s_cp_0_11?_encoding=UTF8&pd_rd_i=B00O3HDA26&pd_rd_r=72QGFP3V3A4BB13KQVEJ&pd_rd_w=gPTus&pd_rd_wg=FlBzF&psc=1&refRID=72QGFP3V3A4BB13KQVEJ

 

I like the round rockers as I find it easier to drill a hole with a spade or step bit vs trying to precisely cut a square hole in one of the plastic panels.  Once you've decided where to mount it the wiring is fairly straightforward.  The wire leading to the rad's thermo switch (TS) is hot with the key on, and all the TS does is ground the circuit.  The rocker switch will do the same.  Since the TS wiring is connected with blade connectors, you'll need a supply of them, both male and female and a bit of wire - I think I used 12 ga.  To start, create an extension wire with male and female ends that will connect both to the hot wire and the center pole of the new switch, bringing power to it.  The center position of the switch sends no power anywhere and will be the "Off" position for the fan.  

 

Now create a 2nd jumper wire that goes from either of the two remaining connectors on the new switch to the TS (again using male /female ends on the jumper).  This position will become the "normal operation" for the new switch as the power will be routed through it to the TS, making it the same current flow as stock, except that it's routed through the new switch.  In this position the TS will control operation of the fan - set and forget. 

 

Finally create a wire with a female connector to connect to the remaining male blade on the new switch.   This wire will go to ground and will complete the circuit, forcing the fan on.  There should be a suitable bolt on the frame or similar that will accept a ring terminal on the opposite end of that wire.  You can reverse the two wires on the outer terminals of the new switch, thus reversing the switch positions that force the fan on, or makes it work normally - dealer's choice on that.   Center is always "fan off".  Do not route the power wire to either of the end terminals on the new switch. 

 

That's about it.  I guarantee that sooner or later you will forget that you either 1.  Left the fan on or 2.  Left if off.  That realization will come as you're wondering why it's getting hot running down the road or getting too hot sitting in traffic.   Once I did that a few times I became more aware and now it's 2nd nature to keep on top of it.  A lighted switch might help do that.

 

If it's a warm day and I know I'm coming up to slow traffic, I turn the fan on well before it would come on normally - that prevents a lot of heat building up unnecessarily.  Then going down the road, if it's getting over 220 where the TS would have it on, I force the fan off, maximizing airflow at speed.  That worked great this summer - brought the temp down from 236 to about 219.   Just keep presence of mind to set back to normal op when fan on / off is no longer needed. 

 

Hope that helps. 

 

edit:

 

This is the one I used:

 

https://www.digikey.com/catalog/en/partgroup/kd-series/20577

 

Switch.JPG

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