Twin cooling fans............wiring?

[robndeb]

My buggy usually runs around 180 to 210 degrees. Once it even got to 230 degrees, but I think there was air in the cooling system that time. Anyway, I noticed that there didn't seem to be much air being produced by the fans. Looking at the wiring, I noticed they were wired in series. I didn't think this was right, so I rewired them in parallel, so each fan received 12 volts. They spun up a lot faster, so I thought all was good, no more running warm. Well, I hadn't run the car since I rewired the fans, until today when I changed the oil, and I noticed the voltage light on the Digidash was reading in the red, with the engine running and the fans on. If I reved it up a bit, it went back into the green, until I turned the lights on, then no matter what I did, it wouldn't come out of the red on the gauge. If I turned the fans off, it went back to green immediately, even with the lights on. Well, I put the fans back to being wired in series and all is good again with the electrical system. Are these fans supposed to be wired in parallel or in series?  What should my normal operating temperature be?  How many watts is the stock stator good for? Sorry for all the dumb questions, and thanks for any replies.

[Boostinjdm]

series doubles the resistance so it draws less power.  less power means less performance.  parallel halves the resistance therefore draws more power and performs better.  parallel would cool better, but it sounds like it is overtaxing your charging system.  could you get away with one really good fan instead of running two?  Fans should be wired with a thermoswitch and relay to be correct.  IMO anyway.

[Engineer]

I would agree with boostin.  I would try just one fan.  With both fans running at half power, I would doubt that they move as much air as one running at full power.  Just my opinion as well, but the only way to know would be to try it. 

You could put the second fan on a manual switch for running only after some hard dunning......  And with it cooler at night, you may never need the second fan when the lights are on.  I would run the second fan through the keyswitch, so it doesn't get forgotten and run the battery down.

[Punkur67]

Also a shroud will help so you dont have "hot spots" on the radiator. You will increase the fans effectiveness and get more cooling from you radiator.

[robndeb]

It has a nice shroud for the twin fans. I may make a new shroud for just one of them and try it then.

[Engineer]

If it was me I would try just running one to see what happened before changing the shrouds.

[Punkur67]

If you just want to try on I would block off the hole where the fan you are not running was with just a simple piece of cardboard and test it out. If you turn off the air will draw through it instead of the radiator. The air is gunna want to travel in the path of least resistance and the open fan will be it and you will not be moving all the air through the radiator. Very simple to test correctly.

[robndeb]

If it was me I would try just running one to see what happened before changing the shrouds.

Sounds like a plan, I will make a cover for the hole and just try one fan.

[Admin]

It is only doing it at idle correct? so it is running the power low in the battery and the system can not keep up... How about just adding the hopped up voltage regulator...

[Admin]

http://www.ricksmotorsportelectrics.com/press/2007-03-06High_Output_Hayabusa_Kit.pdf

[robndeb]

[robndeb]

[Nutz4sand]

Heat takes time. Thats rule number one. Its why you need a thermostat in 97% of the systems to slow the coolant down in the radiator to bleed the heat out of it. (Unless the radiator is far to large)  So one fan running at full power may move more air thru that part but air moving thru the whole radiator will sap out the heat.  Some systems like the Yamaha Banshee are not built with a thermostat but the idea is the harder you run the motor the faster you are going and more air thru the radiator. They also run hot (tend too) and will usually overheat if left to idle for a bit. Its a balance. But in a bigger better system its more controlled for a desired resiult. 

But for your electrical problem pop an amp meter in the line see what they are taking (might have to test each one individually depending on your meter). You might get away with a power increase in the charging system but you may also find two fans that use less juice are what might help you to. Have to figure the cost for each mod (better charging system VS less current fans) and see which is more cost effective and easier for you to implement.

Pop a pic of your fan setup up. Just cause. Just cause we like pics! 

[455bird]

[fabr]

If you just want to try on I would block off the hole where the fan you are not running was with just a simple piece of cardboard and test it out. If you turn off the air will draw through it instead of the radiator. The air is gunna want to travel in the path of least resistance and the open fan will be it and you will not be moving all the air through the radiator. Very simple to test correctly.

Nearly no air will flow through with only one fan running or removed from the shroud.The advise to run one with a sweitch on the other is IMO bad.Either beef the charging system for a few more amps or go to a higher performance single fan that draws fewer amps than the 2 combined do wired in parallel.