time delay switch for radiator aux fan

[voltscastillo]

planning to add an aux electric fan for an old car. first time i'll be doing this.

gusto ko sana malaman kung may switch na mag control sa aux fan na ito, yung parang sa mga bagong kotse ngayon na nag aactivate lang yung fan every 30 seconds or so (hindi parating naka-on) para hindi naman masunog yung fan motor prematurely.

gusto ko sana may controllable switch mounted sa dash, tapos selectable: low (1 cycle per minute), medium (1 cycle per 30 seconds), and high (on all the time). hindi naman kasi maganda yung sobra sobrang cooling... pag maulan or malamig set ko lang sa less cycles...

what do you call this type of switch (if any exist)? cost? alam ko kasi sa aux fans pag on mo ng switch nun derecho on na yun eh.

thanks for any help.

[oj88]

What you want can be done using the 555 timer in astable mode. Play around with R1, R2 and C to achieve the desired duty cycle (how much time the fan is ON) and delay (how much time the fan is OFF). You should use a relay for this circuit to operate the fan.

Of course, the more elegant solution is to use a thermoswitch that will turn the fan on and off as needed.

[CVT]

^^^ Ang walang kamatayang 555 timer....

7909:taunt:

[jick.cejoco]

planning to add an aux electric fan for an old car. first time i'll be doing this.

gusto ko sana malaman kung may switch na mag control sa aux fan na ito, yung parang sa mga bagong kotse ngayon na nag aactivate lang yung fan every 30 seconds or so (hindi parating naka-on) para hindi naman masunog yung fan motor prematurely.

gusto ko sana may controllable switch mounted sa dash, tapos selectable: low (1 cycle per minute), medium (1 cycle per 30 seconds), and high (on all the time). hindi naman kasi maganda yung sobra sobrang cooling... pag maulan or malamig set ko lang sa less cycles...

what do you call this type of switch (if any exist)? cost? alam ko kasi sa aux fans pag on mo ng switch nun derecho on na yun eh.

thanks for any help.

volts,
for hour car to run at optimum efficiency and to minimize pollution, our car has to operate at a range between 190 to 240 degrees or at a target of 215 degrees fahrenheit. keep the pressure in the cooling system to 15 psi. for each 1 psi rise in pressure in your pressurized cooling system, an average of 3 degrees rise in boiling point results. the radiator cap keeps the pressure in the system as would the pressure cooker you have in your kitchen. the antifreeze/coolant solution raises the boiling point and lowers the freezing point of the coolant liquid. to convert your old car to electric cooling fan from the traditional belt driven fan improves expected gas mileage that the engine is not pulling an extra fan load and maintains a narrow band of temperature, the ideal one. to convert your fan system, you do not need to experiment and waste time and money by matching you engine displacement to a newer car and use the newer car's fan size and capacity. you can buy this aftermarket. you will need a 30 ampere N.O. (normally open relay or make type relay) and a fan thermoswitch that you can install at the inlet side of your thermostat housing by tapping a thread big enough for your thermoswitch. the rest is wiring. better still use aftermarket parts that you can buy from jcwhitney or check the internet. they are pretty mch universal.
jick
ase certified master automobile technician
ase certified master heavy duty truck technician
international automotive technician's network

[voltscastillo]

thanks gents

it's a 79 galant with the saturn/astron engine, btw.

me and a buddy of mine tryng to restore it in our free time. we're just about done with the paint, and the engine, now's time for the cooling system and electronics. thankfully, cars of this generation have almost none, apart from the lights and radio, hehehe.

*oj888

yes the thermoswitch system is the cleaner solution. is there a non-oem thermoswitch available sa auto supply stores? if so, does it come equipped with a probe that can be inserted into the thermostat housing (or near it?) or just tapped into the radiator somewhere?

*jick.cejoco

i'm more inclined to rig up this switch ghetto style. but since the thermoswitch alternative seems more reliable, yes i would give it a try. but the car has not used a working, oem thermostat in about a decade, and we forgot about making a provision for a thermoswitch when the tech was putting it all back together after the rebuild.

[oj88]

Volts,

I highly recommend that you read the following article: http://www.aaroncake.net/rx-7/efaninstall.htm

Despite my earlier post, I would suggest that you go for the proper method of installing a radiator fan; which is to automatically turn it on and off using an electric thermostat or thermoswitch. Manual switching, as you'll find out in the article, can be too cumbersome for the driver and inefficient.

[alwayz_yummy]

why not just install a thermo-switch, where in the fan will bill turned on if the temp reaches the preset value and turns off at a preset value also.

dami pa nyung wiring -wiring, thermo switch ay tatap lang between then tapos na...

[oj88]

why not just install a thermo-switch, where in the fan will bill turned on if the temp reaches the preset value and turns off at a preset value also.

dami pa nyung wiring -wiring, thermo switch ay tatap lang between then tapos na...

You're making it too simplistic. You need to have fuses, a relay and a properly calibrated thermostat/switch that will operate the fan at the correct engine temp. Then there's the issue of where to put it (ie. top or bottom of the radiator, before or after the thermostat valve, water inlet or outlet, etc.)

Solutions to seemingly simple problems should still follow best practices.

[jick.cejoco]

You're making it too simplistic. You need to have fuses, a relay and a properly calibrated thermostat/switch that will operate the fan at the correct engine temp. Then there's the issue of where to put it (ie. top or bottom of the radiator, before or after the thermostat valve, water inlet or outlet, etc.)

Solutions to seemingly simple problems should still follow best practices.

oj88,
you are absolutely right. you can not make it too simple. it has to be simple but most of all it has to be safe. it will still need the five components of an autmobile circuit: 1-power source-given, 2-circuit protection-fuse to be added in line,3- control- the fan thermoswitch installed upstream from the thermostat, 4-the conductors- wiring you will have to add on(for this load, 12 AWG(american wire gauge) for the power circuit, 18 AWG for the control circuit, 5-the load- your radiator fan. of course you will have to amplify the signal from the thermoswitch since it can not carry the current the fan loads to it. what yo need is probably a nippon denso M3 or M4 or a circuit open relay for toyota that controls currnet to the fule pump. or if lyou can get a higher current rating power transistor to replace the relay. just make sure the fan rotation is not fighting against the incoming ram air when the vehicle is in motion.
jick
a.s.e. certified master automobile technician
a.s.e. certified maste heavy duty truck technician
international automotive technicians' network

[jick.cejoco]

oj88,
you are absolutely right. you can not make it too simple. it has to be simple but most of all it has to be safe. it will still need the five components of an autmobile circuit: 1-power source-given, 2-circuit protection-fuse to be added in line,3- control- the fan thermoswitch installed upstream from the thermostat, 4-the conductors- wiring you will have to add on(for this load, 12 AWG(american wire gauge) for the power circuit, 18 AWG for the control circuit, 5-the load- your radiator fan. of course you will have to amplify the signal from the thermoswitch since it can not carry the current the fan loads to it. what yo need is probably a nippon denso M3 or M4 or a circuit open relay for toyota that controls currnet to the fule pump. or if lyou can get a higher current rating power transistor to replace the relay. just make sure the fan rotation is not fighting against the incoming ram air when the vehicle is in motion.
jick
a.s.e. certified master automobile technician
a.s.e. certified maste heavy duty truck technician
international automotive technicians' network

just an add-on: the power transistor is of PNP type since the fan thermoswitch is a grounding(negative side) switch
jick

[voltscastillo]

oj88,
...just make sure the fan rotation is not fighting against the incoming ram air when the vehicle is in motion.
jick
a.s.e. certified master automobile technician
a.s.e. certified maste heavy duty truck technician
international automotive technicians' network

that's going to be a problem, because we've no place to put it but the front of the radiator behind the front grille. behind the radiator is the fan belt driven fan...

*oj88

fantastic article. i'm reading it right now, and the related article about the myth of the e-fan. thanks.

*Alwayz

gusto ko nga din sana yung thermoswitch system eh. kaso parang ayoko mag drill ng hole sa water intake piping to insert teh sensor. and even if i do manage to insert a thermoswitch there and seal it properly, where do i tap it? the galant has no ECU control module that would activate the system automatically, pre-programmed. i would have to do more wiring to make it cycle.

[jick.cejoco]

that's going to be a problem, because we've no place to put it but the front of the radiator behind the front grille. behind the radiator is the fan belt driven fan...

*oj88

fantastic article. i'm reading it right now, and the related article about the myth of the e-fan. thanks.

*Alwayz

gusto ko nga din sana yung thermoswitch system eh. kaso parang ayoko mag drill ng hole sa water intake piping to insert teh sensor. and even if i do manage to insert a thermoswitch there and seal it properly, where do i tap it? the galant has no ECU control module that would activate the system automatically, pre-programmed. i would have to do more wiring to make it cycle.

volts,

you might be able to find one thermostat housing from another car with fan thermoswitch with it already. the architecture is pretty much similar to all asian cars, you just have to find the right one or you can use a radiator tube for a nissan sentra with a fan thermoswitch on it. check your local boneyards or surplus parts stores. pertaining the fan, use a pusher fan instead of a pull fan. it goes in front of the radiator or a/c condenser. use the straight blade one since you can reverse polarity and rotational direction without sacrificing volumetric capacity and does not make too much noise and of course narrow straight fan blades have less air drag when not rotating. on the fan thermoswitch, you can pretty much drill and install on the cylinder head closest to the thermostat. good luck hunting at the boneyard or check the world's best search tool: the internet. websites like autoparts.com, kragen's, jcpenny, 4wd.com, etc....
shop using your fingers doing the walking
jick
certified auto
guam

[oj88]

Yeah, you'll be able to find the correct fan configuration (front-mounted, airflow towards the radiator). But whatever you do, don't change the polarity of the fan motor to reverse it's rotation just to satisfy your requirements. Doing so will shorten the life of the fan at best, or cause severe electrical problems at worst.

[jick.cejoco]

Yeah, you'll be able to find the correct fan configuration (front-mounted, airflow towards the radiator). But whatever you do, don't change the polarity of the fan motor to reverse it's rotation just to satisfy your requirements. Doing so will shorten the life of the fan at best, or cause severe electrical problems at worst.

oj88,
i totally understand your confusion. there are push/pull, reversible/reversible rotation aftermarket fans available out there. reversible simply means reversible. one of the reason why the blades are straight so it can be reversed and reduce drag when not rotating. this does not cause the life of the fan to prematurely wear out nor cause "electrical" problems as it was designed for that exact purpose. i have been installing them for years. i say again, for years. the last one i installed was on my 92 toyota previa as a helper push fan.it has been there for years until i decided to park my still serviceable toyota previa as a standby spare vehicle. the motors of this type is isolated meaning, it is grounded or only connected to the negative side through the wire or lead at the connector. i hope this clears one and all confusion pertaining this auxilliary fan question.
jick
a.s.e. certified master automobile technician
a.s.e. certified master heavy duty truck technician
international automobile technicians' network

[alwayz_yummy]

hehehe.. 79 galant naman kotseng paglalagyan, no electronics yan, simpleng kotse. masyado nyu pinahihirapan ang isang simpleng solusyon.. well, ako ayaw ko din ng bubutas ng extra sa pipings.

now kung modern car na sandamukal ang electronics and computers, aba iba ang sasagot ko.

may thermo switches naman na may preset value na mabibili ng OTC...plug and tap lang ayos na.ung mga ginagamit sa aircon ng makina...

since may radiator fan na sya, sure naman na itis installed properly na(w/ relays and stuff) all he needs is what control mechanism to use.

as i recall, si doc wiretap_MD may alam sa ganyang mod. as i know vitara nya ay wala na ung clutch fan at pinalitan nya ng fan w/thermo switch.

[jick.cejoco]

hehehe.. 79 galant naman kotseng paglalagyan, no electronics yan, simpleng kotse. masyado nyu pinahihirapan ang isang simpleng solusyon.. well, ako ayaw ko din ng bubutas ng extra sa pipings.

now kung modern car na sandamukal ang electronics and computers, aba iba ang sasagot ko.

may thermo switches naman na may preset value na mabibili ng OTC...plug and tap lang ayos na.ung mga ginagamit sa aircon ng makina...

since may radiator fan na sya, sure naman na itis installed properly na(w/ relays and stuff) all he needs is what control mechanism to use.

as i recall, si doc wiretap_MD may alam sa ganyang mod. as i know vitara nya ay wala na ung clutch fan at pinalitan nya ng fan w/thermo switch.

always,
as the first thread, the member is asking for help how to do it. i suggest leave it to the professionals. if we are unable to do things because we are not trained, not enough knowledge of technology nor have the experience, let's leave it to who knows. by the way a fan thermoswitch is not electronic component, it is simply a bimetallic switch with two dissimilar metals that have different expansion rates to engage or disengage a mechanical contact. let's go back to basics. this is very basic. just learn as you go if you have not already
jick
certified auto
guam

[oj88]

oj88,
i totally understand your confusion. there are push/pull, reversible/reversible rotation aftermarket fans available out there. reversible simply means reversible. one of the reason why the blades are straight so it can be reversed and reduce drag when not rotating. this does not cause the life of the fan to prematurely wear out nor cause "electrical" problems as it was designed for that exact purpose. i have been installing them for years. i say again, for years. the last one i installed was on my 92 toyota previa as a helper push fan.it has been there for years until i decided to park my still serviceable toyota previa as a standby spare vehicle. the motors of this type is isolated meaning, it is grounded or only connected to the negative side through the wire or lead at the connector. i hope this clears one and all confusion pertaining this auxilliary fan question.
jick
a.s.e. certified master automobile technician
a.s.e. certified master heavy duty truck technician
international automobile technicians' network

Hi Jick,

I only mentioned that because the way things are here, Volts would probably be looking for pre-used aux fans. These used fans were most likely pulled out of old cars and therefore, OEM in nature and not the aftermarket kind you described. Being OEM, they're only designed for single polarity and airflow. At least, that's what I think.

[voltscastillo]

hehehe.. 79 galant naman kotseng paglalagyan, no electronics yan...

may thermo switches naman na may preset value na mabibili ng OTC...plug and tap lang ayos na.ung mga ginagamit sa aircon ng makina...


as i recall, si doc wiretap_MD may alam sa ganyang mod. as i know vitara nya ay wala na ung clutch fan at pinalitan nya ng fan w/thermo switch.

boss alam mo iniisip ko yan. meron ako dito mga thermoswitch na galing sa aircon din eh, yung bakal na may probe, nilalagay sa evaporator pag ayaw na mag automatic yung aircon. i have 3 of those, no thanks to a stupid tech who insisted on converting my cars to that switch nung hindi nya mapatino yung automatic function ng a/c compressor...

pero don't those switches work at cold temps lang? they're mechanical (at leas, they look like purely mechanical). at pre-set cold temp i-off nya compressor, tas pag uminit, on ulit.

will those work the other way round? hmm... 600 isa nun e, i may have to ask the tech re: my desired application.

anyway, i'll try searching for that mod you spoke of here.

[bambino]

Hi Jick,

I only mentioned that because the way things are here, Volts would probably be looking for pre-used aux fans. These used fans were most likely pulled out of old cars and therefore, OEM in nature and not the aftermarket kind you described. Being OEM, they're only designed for single polarity and airflow. At least, that's what I think.

i agree

LICENSED CLASS A AUTO TECH
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CERTIFIED,SPECIALIST A/C ELECTRICAL TECH
SPECIALIST ALTERNATOR STARTER REBUILDING
EDUCATOR , TECHNICAL ADVISER TO GARAGES
IATN ACTIVE MEMBER

[jick.cejoco]

Hi Jick,

I only mentioned that because the way things are here, Volts would probably be looking for pre-used aux fans. These used fans were most likely pulled out of old cars and therefore, OEM in nature and not the aftermarket kind you described. Being OEM, they're only designed for single polarity and airflow. At least, that's what I think.

oj88,
if the 79 gallant is of north/south orientation, or engine is inline with transmission from front to rear, there should be ample space for either push fan or pull fan. if you use a condenser fan, it is installed as a push fan in front of the airconditioner as we used to call them or in front of the radiator for non airconditioned cars, this one you don't need to worry reversing rotation and polarity. if you have ample room behind the radiator, a used radiator fan from a surplus and don't need reversing polarity and rotation. i don't see a problem here. it is very advisable to use any mitsubishi setup of a newer vehicle and transplant components. they should be compatible without organ rejection. you might even find a thermostat housing that has a fan thermoswitch installed on it. the thermostats of asian cars is about 40mm. similar architecture.


jick
guam community college