Bypass your radiator fan

[Tejas]

Check out this thread http://www.vfrdiscussion.com/forum/index.p...c=22997&hl=

post #6 shows what i did to help this problem and there are some thoughts on spinning the fan backwards.

[thereisnospoon]

now we're talkin thanks for the link!

Check out this thread http://www.vfrdiscussion.com/forum/index.p...c=22997&hl=

post #6 shows what i did to help this problem and there are some thoughts on spinning the fan backwards.

[Brown81]

Man, this is what I need to do to my '94. It absolutely HATES traffic on hot days. Temp just skyrockets!!

I wish I wasn't such a 'tard when it comes to electrical. I don't feel confident I could do it without screwing up. :blink:

[Guest vfrvern]

I'm thinking of modifying this slightly... to turn the fan off. On the way home yesterday 104 degrees + 80mph = 230 degrees of engine temp. Since the fan was running the whole time fighting the airflow I think it needs some attention.

Has anyone made the fan spin backwards? Probably more trouble than its worth, but pulling the air in with the fan so its more "comfortable" is silly... The left shin is rather warm anyway.

HS, can you repost your pics? I know its been a while... Thanks

This is EXACTLY the problem I'm having. I need to be able to get the fan to turn off at highway speeds. The next post in this thread has a link but it is broken.

Edited May 1, 2007 by vfrvern

[Guest jbbcd]

<font color='#000000'>FWIW, I did the same mod on my dear departed '86 and it worked great for when you got stuck in traffic. Switch the fan on BEFORE the motor gets hot. It seems to help if you get a jump on the heat.</font>

<font color='#000000'>Yea that was the whole idea, turn it on before it gets overheated, next time I am tuning my PC2 or somthing I just switch on the fan, or before I overheat in the stop and go traffic. It seems to be much cheaper than the $40 replacement thermo switch.

I would like to point out that having the fan on at speed is counter productive since it sucks air into the radiator from the side vents, once you get going at speed the air goes from the the wheel well and out thru those vents the opposite way!  Having on the fan would just work against the the natural flow when your riding at speed.</font>

[HispanicSlammer]

I would like to point out that having the fan on at speed is counter productive since it sucks air into the radiator from the side vents, once you get going at speed the air goes from the the wheel well and out thru those vents the opposite way!

I should pointout that the thermo switch runs that way anyhow, at speed it runs like that by honda spec. The radiator gets hot it turns the switch on, fan runs, at speed or not.

[Guest jbbcd]

1986 750 vfr: So when my fan is running, its suppose to be forcing air forward(from rear to front??) sucking air in through the side vents to the front of the bike??

When my fan is running, the air is pulled from the front of the bike to the rear (this is wrong??)

Then my fan blades are turning the wrong way when the fan is on.

Is this correct??

[Auspanglish]

Hey there Vifferarians... trying my best at a schematic of your bypass harness, is the following basically what HS has done?

Yeah, I know, the proportions are out of whack... that's just my lack of finess with photoshop...

Just to resurrect a question from this thread... would it be possible to include some way to manually turn the fan off for that scenario when you're finally able to accelerate up to over 80 km/h but have been stuck in traffic for a while and the fan is running, since at those speeds the natural airflow would be competing with the fan's airflow and I've definitely noticed that when this occurs it can also take some time for things to cool down... and what I'm looking for is having her run as cool as possible as often as possible... would that involve perhaps another long section of cable upstream of the splice you've invented, with an in-line switch for cutting off the supply of power to the whole assembly... like this:

Or is it just not worth it?

[redmarque]

Just looking at this thread again, because I've had the fairings on my 98 off and just replaced a faulty thermostat.

Auspañol you're idea of being able to turn the fan off would work perfectly! :fing02:

[Tightwad]

Just looking at this thread again, because I've had the fairings on my 98 off and just replaced a faulty thermostat.

Auspañol you're idea of being able to turn the fan off would work perfectly! :fing02:

:laugh: Indeed this is a nice option. I have been playing with more high tech options that would allow a temporary override, but I think this would be better in most cases...just not as fun.

I have the fairings off my bike (again) doing a headlight mod, so If I remember I will take pictures of the wires needed, so they are easier to find. Should be easy to mod!

[Tightwad]

I put my drawing skills to work today, after figuring out how to incorporate both the "Manual off" and "Forced on" options into one DPDT switch.

The switch is the lines at the top left, switch up would turn the fan on, switch down the fan would never come on. I pictured a "normal" 5 wire relay, because they are cheaper than a 4 wire NC relay.

[redmarque]

I put my drawing skills to work today, after figuring out how to incorporate both the "Manual off" and "Forced on" options into one DPDT switch.

The switch is the lines at the top left, switch up would turn the fan on, switch down the fan would never come on. I pictured a "normal" 5 wire relay, because they are cheaper than a 4 wire NC relay.

Using the relay would mean that 6th gen's could use this mod too, as the relay would switch the high current?

[Guest onedowneaster]

Hi all ya hot runnin VFR dudes, If this has already been said ,my apologies. Anyway,I couldnt agree more, but whatever it takes, the fan really needs to come on sooner so it can get a jump on the heat. Has anyone ever checked if someone makes a thermo swithch that is adjustable or one that would come on sooner? My second comment is ,I dont think we need to spin the fan motor backwards. I recently bought a new Honda fan blade that has a reverse pitch on it. The fan is made to pull air out of the engine area,thus it will go with the flow. If anyone is interested I can let you know the Honda P/N . eddie

[dogman]

Hi all ya hot runnin VFR dudes, If this has already been said ,my apologies. Anyway,I couldnt agree more, but whatever it takes, the fan really needs to come on sooner so it can get a jump on the heat. Has anyone ever checked if someone makes a thermo swithch that is adjustable or one that would come on sooner? My second comment is ,I dont think we need to spin the fan motor backwards. I recently bought a new Honda fan blade that has a reverse pitch on it. The fan is made to pull air out of the engine area,thus it will go with the flow. If anyone is interested I can let you know the Honda P/N . eddie

Is that a fan from a VTR1000?

That seems like a worthwhile mod to me.

Pity its such a big deal to change the fan blade

[Kel]

1986 750 vfr: So when my fan is running, its suppose to be forcing air forward(from rear to front??) sucking air in through the side vents to the front of the bike??

When my fan is running, the air is pulled from the front of the bike to the rear (this is wrong??)

Then my fan blades are turning the wrong way when the fan is on.

Is this correct??

Your 86' should pull air from the front. These guys are talking about the side radiator setup. I've had a switch on my kR for 20 years now. It never gets hot when the switch is turned on early. In dead stopped traffic, my buddies kR will show 3/4 on the gauge while mine is at 1/2.

[Guest sweet97]

I had a manual bypass switch on my V65 Magna that worked pretty well. I used this for a year with great results. Then, someone over on V4HondaBBS.com found that a fanstat switch from an Accura Integra (i forget what year) would screw right into my rad, and lower the fan turn-on temp by about 20 degrees! I installed one of these, and the bike hasn't even thought about overheating since. Maybe there is a similar solution here? Honda Civic, Accord, etc? Might be worth checking out....

Dave P.

[Knife]

I had a manual bypass switch on my V65 Magna that worked pretty well. I used this for a year with great results. Then, someone over on V4HondaBBS.com found that a fanstat switch from an Accura Integra (i forget what year) would screw right into my rad, and lower the fan turn-on temp by about 20 degrees! I installed one of these, and the bike hasn't even thought about overheating since. Maybe there is a similar solution here? Honda Civic, Accord, etc? Might be worth checking out....

Dave P.

I'll bet Tightwad could find one and put a kit together for us. Tightwad?

[Tightwad]

I had a manual bypass switch on my V65 Magna that worked pretty well. I used this for a year with great results. Then, someone over on V4HondaBBS.com found that a fanstat switch from an Accura Integra (i forget what year) would screw right into my rad, and lower the fan turn-on temp by about 20 degrees! I installed one of these, and the bike hasn't even thought about overheating since. Maybe there is a similar solution here? Honda Civic, Accord, etc? Might be worth checking out....

Dave P.

I'll bet Tightwad could find one and put a kit together for us. Tightwad?

Other than possible changing a connector, this would be a simple modification. It would help if someone who worked for a dealer could investigate, as the only way most of us could do it would be by trial and error. I know when I sold autoparts we had specs for all the sensors etc. Back then I could have found one that worked, but I no longer have access to all those books etc.

[Tightwad]

I put my drawing skills to work today, after figuring out how to incorporate both the "Manual off" and "Forced on" options into one DPDT switch.

The switch is the lines at the top left, switch up would turn the fan on, switch down the fan would never come on. I pictured a "normal" 5 wire relay, because they are cheaper than a 4 wire NC relay.

Using the relay would mean that 6th gen's could use this mod too, as the relay would switch the high current?

The 98 and the 02 models use the same thermo switch. The Relay is really not needed, but it reduces the switch count to 1. Both bikes work by grounding the fan using the Thermo switch, this just allows you to do it earlier, or not at all.