electric fans
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Joined: Jul 2002
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From: WISCONSIN
Dave at FAL told me to set my fans at 192* so they have a *head start* also but I'm with SSCULLY on setting the fans to come on at 200-202*. That way the fans aren't working against the thermostat/radiator in my opionion. I have been having no problems with mine at 200* and the fans only run when they need to and allow the radiator to do it's job it's intended to do with the thermostat open and the truck moving, that being, cool the coolant.
btw - my AC blows Cold, Cold, Cold!
btw - my AC blows Cold, Cold, Cold!
Technical Article Contributor
Joined: Dec 1997
Posts: 9,417
Likes: 11
From: Windsor,Ontario,Canada
hapynzap,
If you think about how the cooling system works you might understand that a -3̊ difference in temp will mean that the fans will still come on just after the thermostat opens.
On initial warm up the coolant in the rad is colder than the coolant in the engine. The only thing heating up the rad is the coolant in the upper and lower rad hoses. It would take a long time for coolant to heat to 193̊ if the thermostat remained closed. When the thermostat opens it allows the hot coolant 195̊+ to ender the rad. The coolant in the rad hose is pushed out of the way and the hot coolant heats the probe and within seconds the rest of the coolant in the rad. The rad coolant is now at 195̊+ The fans turn on a few seconds after the thermostat opens and has to cool a rad that is at 195̊+. If you set the sensor to turn on at 200̊+ the fans will have to cool a rad that is 200̊+. The fans will work longer and harder to cool a hotter rad. When you are in stop and go traffic your fans will run more because they will start later than a fan set at a lower
temperature. If you set your fans to run at too low temperature they will run continuously. Regardless of the traffic conditions. They may even run when you are on the highway. Regardless of the coolant temperature in the rad the thermostat will keep your engine around the 200̊ mark. FWIW I have mine set to turn on at around 185̊ I am still trying to get it right.
Regards
Jean Marc Chartier
If you think about how the cooling system works you might understand that a -3̊ difference in temp will mean that the fans will still come on just after the thermostat opens.
On initial warm up the coolant in the rad is colder than the coolant in the engine. The only thing heating up the rad is the coolant in the upper and lower rad hoses. It would take a long time for coolant to heat to 193̊ if the thermostat remained closed. When the thermostat opens it allows the hot coolant 195̊+ to ender the rad. The coolant in the rad hose is pushed out of the way and the hot coolant heats the probe and within seconds the rest of the coolant in the rad. The rad coolant is now at 195̊+ The fans turn on a few seconds after the thermostat opens and has to cool a rad that is at 195̊+. If you set the sensor to turn on at 200̊+ the fans will have to cool a rad that is 200̊+. The fans will work longer and harder to cool a hotter rad. When you are in stop and go traffic your fans will run more because they will start later than a fan set at a lower
temperature. If you set your fans to run at too low temperature they will run continuously. Regardless of the traffic conditions. They may even run when you are on the highway. Regardless of the coolant temperature in the rad the thermostat will keep your engine around the 200̊ mark. FWIW I have mine set to turn on at around 185̊ I am still trying to get it right.
Regards
Jean Marc Chartier
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Joined: Dec 1969
Posts: 1,734
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From: Nor-Cal,USA
OK this question goes out to anyone with the FAL 270 that has wired a illumintaed switch to manually shut the fans OFF in any condition even with the A/C running such as for water crossings and such. JMC i know you have this but since you DO NOT have the FAL am not sure you can help. FLEX-A-Lite told me to save some money and just buy any illumintaed swicth at my local Auto parts store so I did that and then went to install it according to the FAL directions and when I hit the switch to shut the fans off not only did it not work it blew one of my 50 amp fuses under the hood so now my truck won't start. until I can get a way to the parts store to buy a new fuse. So how has everyone wired there fans with the manula shiutoff swicth and does your switch light up when you turn the fans off. Also if it does light up where did you get your power from ? Did youi runa power wire directly from the battery? I tied into the ignition turn on for my off road lights which I think may have been the problem should I just run a wire directly to my battery or will this casue damage?
Thanks
Richard D.
Thanks
Richard D.
Technical Article Contributor
Joined: Dec 1997
Posts: 9,417
Likes: 11
From: Windsor,Ontario,Canada
Richard,
Does your switch come with lables on the contacts? If they are numbered 1 - 2 - 3 then terminal #1 goes to the controller #2 goes to ground and #3 goes to a 12v power source. If they are labled OFF on one end and ON at the other end, the OFF end terminal goes to the controller the middle contact goes to ground ant the terminal at the ON end goes to a 12v power supply. If the switch has no lables then turn it off and the terminal that is at the end where the rocker is lowest is the OFF end. Apply the logic from the OFF ON marked switch.
JMC
Does your switch come with lables on the contacts? If they are numbered 1 - 2 - 3 then terminal #1 goes to the controller #2 goes to ground and #3 goes to a 12v power source. If they are labled OFF on one end and ON at the other end, the OFF end terminal goes to the controller the middle contact goes to ground ant the terminal at the ON end goes to a 12v power supply. If the switch has no lables then turn it off and the terminal that is at the end where the rocker is lowest is the OFF end. Apply the logic from the OFF ON marked switch.
JMC
Technical Article Contributor
Joined: Dec 1997
Posts: 9,417
Likes: 11
From: Windsor,Ontario,Canada
Richard,
I forgot to ask. Which fuse did you blow? Taking power from a coils circuit can cause problems. Coils do not like other power leaches in tied into their circuits.
JMC
I forgot to ask. Which fuse did you blow? Taking power from a coils circuit can cause problems. Coils do not like other power leaches in tied into their circuits.
JMC
Senior Member
Joined: Dec 1969
Posts: 1,734
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From: Nor-Cal,USA
Talked with Flex-a-lite and turns out I cannot use the switch I purchased for 3.00 and have it light up,which is my problem so I had to purchase the FAL part# 31148 wich is a ground illuminated switch. The switch I have works when i wire it with just two wires the ground wire then the grnd wire that goes to terminal 5 on the VSC. JMC I blew one of the Big MAX 50 amp fuses that controls the ignition on/off. Everything is a ok now since I put a new one in. I am now witing on the FAL swicth to arrive so I can install it. You know I knew when I was hooking the switch up something didnt seem right buit I went ahead and hooked it up anyway. MAN I WAS FREAKING OUT when my truck would not start no rqadio came on with the key in the on pos but it would come on when the key was turned back to ACC. I really thought I screwed something up bad luckily it was just a fuse
Richard D.
Richard D.
Senior Member
Joined: Dec 2002
Posts: 1,558
Likes: 3
From: Eastern TN
Guys, for what it's worth:
I did not have a temp gauge when I installed my FAL 270. To adjust the fans, I used the following method (I admit it is rather crude) :
I drove my truck for 20 miles or so on a country road to get the entire engine and tranny up to normal operating temperature.
I very quickly stopped and popped the hood. I then adjusted the VSC until the fans kicked on. I then drove another 5 miles or so and pulled over. The fans were running, so I adjusted them up until they turned off and started driving again. After a couple of miles, I pulled over and timed with my watch. After 45 seconds of idling, the fans kicked on. Soon as I started driving, they kicked off.
I now have a temp gauge and can tell you that my truck runs just under 195* on the interstate. When I stop, the fans kick on about 30-45 seconds afterwards. If I travel 30 MPH or faster, they never run.
Don't know how accurate my set-up is, but it seems to keep the engine right at the 195* mark (Obviously the thermostat sets the temperature; the fans just help keep it there).
On a separate note: I posted the other day about my FAL fuse blowing and my engine getting up to 245*. It does not appear to have hurt anything, but I did make the following changes to my installation:
I installed 2 separate 30 amp fuses (1 to each fan) instead of the single 40 amp fuse included with the kit. I have been unable to determine what caused the original fuse to blow, but I am not willing to risk my engine in such a manner again. As I've seen Neal say many times before, with 1 fan your screwed if anything goes wrong. Well, the same applies to 2 fans if you only have 1 power source for them.
I also installed wiring across each fuse that goes to a blinking red LED in the cab. If either fuse blows again, I'll get a little indication of it before the temp gauge ends up being sky-high.
I am in the middle of designing a circuit for more intelligent fan control. I'm going to set it up to analyze several factors of the vehicles' operating environment, including the speed of the vehicle, into the calculations as to whether or not the fans should run. Once I finish, I'll post what I come up with (if anyone is interested).
B-Man
I did not have a temp gauge when I installed my FAL 270. To adjust the fans, I used the following method (I admit it is rather crude) :
I drove my truck for 20 miles or so on a country road to get the entire engine and tranny up to normal operating temperature.
I very quickly stopped and popped the hood. I then adjusted the VSC until the fans kicked on. I then drove another 5 miles or so and pulled over. The fans were running, so I adjusted them up until they turned off and started driving again. After a couple of miles, I pulled over and timed with my watch. After 45 seconds of idling, the fans kicked on. Soon as I started driving, they kicked off.
I now have a temp gauge and can tell you that my truck runs just under 195* on the interstate. When I stop, the fans kick on about 30-45 seconds afterwards. If I travel 30 MPH or faster, they never run.
Don't know how accurate my set-up is, but it seems to keep the engine right at the 195* mark (Obviously the thermostat sets the temperature; the fans just help keep it there).
On a separate note: I posted the other day about my FAL fuse blowing and my engine getting up to 245*. It does not appear to have hurt anything, but I did make the following changes to my installation:
I installed 2 separate 30 amp fuses (1 to each fan) instead of the single 40 amp fuse included with the kit. I have been unable to determine what caused the original fuse to blow, but I am not willing to risk my engine in such a manner again. As I've seen Neal say many times before, with 1 fan your screwed if anything goes wrong. Well, the same applies to 2 fans if you only have 1 power source for them.
I also installed wiring across each fuse that goes to a blinking red LED in the cab. If either fuse blows again, I'll get a little indication of it before the temp gauge ends up being sky-high.
I am in the middle of designing a circuit for more intelligent fan control. I'm going to set it up to analyze several factors of the vehicles' operating environment, including the speed of the vehicle, into the calculations as to whether or not the fans should run. Once I finish, I'll post what I come up with (if anyone is interested).
B-Man