coolant fan question?

hey ya'll!
just wondering if anybody has any suggestions for my 84 vf750f cooling fans? they work allright, but seem to kick on too late when the temp gage is pretty much to the top. I would really like them to kick on sooner and not wait until the bike is already too hot! I could put in a toggle switch somewhere and turn them on when i want but i would also like to keep the bike as original as possible. Just flushed the coolant and checked my puke bag and did all the normal maintenance stuff but am perplexed as to why the fans dont come on sooner? Are they this way from the factory? I dont know at what temp they actually kick on as the gage has no numbers on it but I think it is to late! Anybody ever put a different fan sending unit in their bike with a lower turn on temp? If so, what would the part number be? I would like to see them kick on at 170-190 and not wait until its already to late to sufficiently cool the engine. If I am on the go, the bike never overheats, but in stop and go traffic its another story! I would think with 2 radiators, this shouldn't even be an issue! Any suggestions?
Thanks! PEACE
Devonshire

 

I have an '83 VF750F. I put a switch on it. I didn't want it to get so hot before the fans kicked on. It just takes a small toggle switch. You can mount it anywhere you want out of sight. Just wire it to the the sending unit. I left my sending unit hooked up incase I was to forget to turn it on.
The fan on my '07 doesn't come on until 221F, but I guess I'll leave that one alone. I like to keep my '83 as cool as possible.

 

Hey Devonshire,
I use to have a 84 750f a few years back and i ran into this also, there is a fan relay that might be bad because one fan comes on for lower temps and the other comes on when it gets higher my bike had two fans althow i have heard that they came with one fan also ?, also the senson might be week and need to be replaced, i put on a adjustable sensor but cant remember where i got it ?

 

thanks eddie and speed.
where would i find the fan relay? underneath seat in back by those other relays? how would i go about wiring a toggle switch? where would i splice it into? any help with this is much appreciated. i really love my bike and want it to run cooler!
thanks! PEACE
devonshire

 

I dont remember where it was sorry i wanted to say by the head light but not sure, as for the fan wiring well what i did was at the sensor tap into each wire and run your switch between the two and put the switch anywhere you want just so it is easy to get to and out of the way ?

 

the prob is that my sending unit is a single wire. is it possibly grounded to the frame like a car would be? if so, then i could possible just run a switch parallel with it and ground the switch to the frame as well. i would really only want to put a switch in if i absolutely have to. i plan to upgrade to a "newer" VFR next year and would like to sell my 84 so i would like to keep it as stock as possible but if switching is my only option, then thats what i will do!
Thanks! PEACE
devonshire

 

then ground that wire threw a switch but leave it hooked up

 

thanks speed. i got your message and know what your talking about. i will probably have to do the switch thing just to keep my bike cool enough for me to be comfortable with it! Besides, someone has to keep the classics alive because without the VF's, there wouldn't be a VFR!
Thanks! PEACE
devonshire

 

The easiest way to wire the switch is to run 2 wires from the 2 poles on your new toggle switch to the 2 wires on the temp sender on the bottom of the lower radiator.
This fools the fan into thinking the temp sender is hot enough to turn on. When cool the sender wires are not connected, when hot, the sender simply connects these 2 wires. When you flip the switch, it merely connects the wires together. A piece of speaker wire will have 2 wires molded together and will work fine for this. All you have to do to turn the fan on, is to connect the wires at the sender together. If you want to test this, unplug the sender, you will see 2 holes in the plug. Get a short jumper wire and use it to connect the 2 holes together. With the key on, the fan will run, hot or not. Wire the switch so it will connect these wires when on, and disconnect them when off. Route the wire carefully. The exhaust is close and will melt the wires if too close.

 

isint that the sending unit for the temp guage? if i connect those two wires via a switch, wont i get a false guage reading? or am i mistaken in thinking the sensor on the thermostat housing is for the fans? maybe im just confused. i guess that makes sense now that you mention the sending unit on the bottom of the lower readitor because why would you need more than one wire to run the guage! thanks for all the input! i guess i just had a brain fart!
Thanks a million! PEACE
devonshire

 

The sender on the thermostat housing is for the guage (single wire). The one on the lower radiator is for the fans (2 wires). Just connect the 2 wires at the bottom of the bottom radiator, and the fans will run, as long as the switch is on.

 

thanks to people on this forum, yet another "old" ceptor will be saved for history! Thanks again because i really love this bike!
PEACE
devonshire

 

The switch on my fan works great! I'm glad I did it. Anytime I see heavy traffic ahead, I flip the switch and don't need to worry about when the fan will kick on.