Not sure where this should be posted so though I would just post it in Toyota.
I don't know stuff all about aircon so hoping someone can help. On my 1995 kzn130 Surf there is an aircon radiator and an additional fan on the left hand side of it (looking from the front). What is this fan for? Is it solely used when the aircon is turned ON to draw more air (aiding the viscous fan) through the aircon radiator to help produce ice cold air? Does it therefore also pull more air through the engine radiator thus cooling that down more too?
If all of the above is true, could it be beneficial to hard wire a switch to this aircon fan which can be turned ON when offroading or towing where additional cooling is required? If it works that well to get the aircon so icey and cold it must work relatively good in conjunction with the viscous fan? And it would pull air right through both radiators quite efficiently I assume seeing as how it is electric?
Just a thought I had last night, wondering if it works like that or not
not sure with kz's but its aircon fan but also comes on with trans overheat or engine overheat. the reason its in that odd place is its right above radiator water outlet. some people have found out that they have had the wrong fan fitted and it blows the wrong way. something worth checking if you have overheating issues.
Hmmm ok will check out which way it blows tomorrow hopefully. Yea I am thinking it should work, but then Again i have heard of some cars overheating when the AC is turned on....so not quite sure how AC would make anything run hotter? Need someone who knows how AC works to give me a definite answer lol don't want to go ahead and do it and feck something up haha.
EDIT: actually that wouldn't be an issue as only the fan would be on not the AC with that switch in there, so having 2 fans running in those positions would surely help force air through right? Has anyone ever done something similar i.e. keeping the viscous and maybe installing an elec fan on the opposite side of the rad to aid cooling? If so was it successful?
the reason that cars run hotter when ac is turned on is because essentialy the air is being heated up by the air con radiator before its hitting the engine radiator, therefore not having the same cooling properties.
im thinking about taking my aircon out anyway, when its a hot day thats what the windows are for (mind you my trucks a 1990 that heats up the truck on the coolest settings)
either that or using the radiator for something else.
Dirtydog wrote:the reason that cars run hotter when ac is turned on is because essentialy the air is being heated up by the air con radiator before its hitting the engine radiator, therefore not having the same cooling properties.
im thinking about taking my aircon out anyway, when its a hot day thats what the windows are for (mind you my trucks a 1990 that heats up the truck on the coolest settings)
either that or using the radiator for something else.
Yea never use my AC but not too keen on ripping it out.
Ok, so the AC condensor/radiator itself gets hot when the AC is turned ON, thus the air getting pulled thru to the engine rad is heated, but with the AC OFF the AC rad would be cool thus having AC OFF and AC fan ON would aid in pulling cool air thru? After all when the AC is off the viscous fan is pulling air thru the AC rad anyway so it must stay cool when it is turned OFF? Or am I wrong and the AC rad always stays hot so it is best to not aid in pulling more hot air thru?
PS never use my AC especially when offroading and truck is hot.
AC rad is cold when not being used. Turning the fan on would be beneficial at slow vehicle speed as long as the fan is pushing air the correct way and not acting against the viscous fan.
Btw, it's not the fan and rad that make the AC freezing cold, they just bring the temp down to a more manageable temperature for the rest of the system. The cooling of the gas also drops the pressure so it doesn't blow up!
Dirtydog wrote:the reason that cars run hotter when ac is turned on is because essentialy the air is being heated up by the air con radiator before its hitting the engine radiator, therefore not having the same cooling properties.
im thinking about taking my aircon out anyway, when its a hot day thats what the windows are for (mind you my trucks a 1990 that heats up the truck on the coolest settings)
either that or using the radiator for something else.
It would make a good trans cooler.
already has one was thinking i might just take it out, cause its not really being used and is just restricting airflow to rad...
evilknieval69 wrote:AC rad is cold when not being used. Turning the fan on would be beneficial at slow vehicle speed as long as the fan is pushing air the correct way and not acting against the viscous fan.
Btw, it's not the fan and rad that make the AC freezing cold, they just bring the temp down to a more manageable temperature for the rest of the system. The cooling of the gas also drops the pressure so it doesn't blow up!
Yep elec AC fan sucks air towards the engine, I would be worried if it did the opposite! And yep that is what I am wanting to use it for, slow speeds when on the beach or bush wacking and the truck temp gets up there.
Going to look at a hard wired switch today or this weekend! Wonder if anyone else has ever done this before haha. It is a pretty decent sized fan so should work quite well for additional cooling.
Its a very easy mod to do. Install a switch on dash. Run 2 wires from this switch to where the single wire goes to on top on the AC compressor. Cut this wire a cpl of inches before comp, then join a wire from switch to each end. When switch is in "on" ( contacts closed) position AC will operate as normal. When switch is "off" ( contacts open) position AC compressor will not engage but front electric fan will operate.
Wouldnt it be better to just run a switch directly to fan to turn it on/off independently? Would your way mean I have to press the AC button ON as well as the new switch to OFF to make the fan go without the AC going?
Dirtydog wrote:i reakon just wiring it to the on off switch would be fine, aslong as ya can figure out what wires which (if it has more than 2)
some fans have four wires (well when it comes to computors etc) but generaly 2 or 3, havnt got a car with electric fans so i cant say lol
Yea had a look at mine this arvo when I was doing my trans cooler it just has 2 big fat wires on the front in the middle guessing power and ground? Thinking of just tapping into the power wire, run it to switch, then from switch to head unit 12v batt/power wire or something? So when switch is off it does nothing, when switch is on it will be running 12v from batt/headunit to fan and will fire it up whether truck is on or off, only thing is will have to make it a switch that lights up so i domt leave it on and run the batts dead
bronx89 wrote:Wouldnt it be better to just run a switch directly to fan to turn it on/off independently? Would your way mean I have to press the AC button ON as well as the new switch to OFF to make the fan go without the AC going?
Was way wrong. Both wires show power on test light, wtf? When i ground one terminal of fan end of plug and 12v other it spins, if i ground other terminal and 12v other it spins opposite way. So why does the test light show both wires on the fan as having power? The ground sparked a bit on each way round but not sure if that was cause i was using speaker wire on surface rusted bare metal to ground lol.
Anyone know which is which and if it is safe to wire a 12v supply in there via a switch to control it? Really not wanting to put a switch on the compressor meaning i have to flick 2 switches to get the fan going
bronx89 wrote:Was way wrong. Both wires show power on test light, wtf? When i ground one terminal of fan end of plug and 12v other it spins, if i ground other terminal and 12v other it spins opposite way. So why does the test light show both wires on the fan as having power? The ground sparked a bit on each way round but not sure if that was cause i was using speaker wire on surface rusted bare metal to ground lol.
Anyone know which is which and if it is safe to wire a 12v supply in there via a switch to control it? Really not wanting to put a switch on the compressor meaning i have to flick 2 switches to get the fan going
^^^ This is why the below was suggested. Control circuits can get tricky, and if not done right can... well just be a fark up. If you do the homework, find some drawings for your ac system, post up a pic of them, and I can tell/suggest how you can do it
tallsam66 wrote:
bronx89 wrote:Wouldnt it be better to just run a switch directly to fan to turn it on/off independently? Would your way mean I have to press the AC button ON as well as the new switch to OFF to make the fan go without the AC going?
bronx89 wrote:Was way wrong. Both wires show power on test light, wtf? When i ground one terminal of fan end of plug and 12v other it spins, if i ground other terminal and 12v other it spins opposite way. So why does the test light show both wires on the fan as having power? The ground sparked a bit on each way round but not sure if that was cause i was using speaker wire on surface rusted bare metal to ground lol.
Anyone know which is which and if it is safe to wire a 12v supply in there via a switch to control it? Really not wanting to put a switch on the compressor meaning i have to flick 2 switches to get the fan going
Quite common for toyota switches to be earths not power feeds, so your fan will have constant 12V to it and the switch will complete the circuit by creating the earth when turned on.
I have had a look online for the AC wiring diagram and cannot find jack, very annoying! May have to do the compressor power switch for now until i can sort out the direct fan switch.
Ay idea where i would find the AC wiring diagram specifically for the fan?
bronx89 wrote:Was way wrong. Both wires show power on test light, wtf? When i ground one terminal of fan end of plug and 12v other it spins, if i ground other terminal and 12v other it spins opposite way. So why does the test light show both wires on the fan as having power? The ground sparked a bit on each way round but not sure if that was cause i was using speaker wire on surface rusted bare metal to ground lol.
Anyone know which is which and if it is safe to wire a 12v supply in there via a switch to control it? Really not wanting to put a switch on the compressor meaning i have to flick 2 switches to get the fan going
Quite common for toyota switches to be earths not power feeds, so your fan will have constant 12V to it and the switch will complete the circuit by creating the earth when turned on.
bronx89 wrote:Was way wrong. Both wires show power on test light, wtf? When i ground one terminal of fan end of plug and 12v other it spins, if i ground other terminal and 12v other it spins opposite way. So why does the test light show both wires on the fan as having power? The ground sparked a bit on each way round but not sure if that was cause i was using speaker wire on surface rusted bare metal to ground lol.
Anyone know which is which and if it is safe to wire a 12v supply in there via a switch to control it? Really not wanting to put a switch on the compressor meaning i have to flick 2 switches to get the fan going
Quite common for toyota switches to be earths not power feeds, so your fan will have constant 12V to it and the switch will complete the circuit by creating the earth when turned on.
But when turned on both wires had 12v?
Any wire with electricity flowing through it, (ie in a closed/ working circuit) will give you a positive reading, even though you are testing an earth wire the 12 volts still has to flow through the wire to get to the chassis/earth to complete the circuit.
If that makes sense?
Last edited by Smurf on Sun Dec 16, 2012 8:26 am, edited 1 time in total.
tallsam66 wrote:Until you figure it out you could always unplug the wire ontop of AC compressor & use AC push button in cab to turn fan off n on.
was just about to sujest the same thing, easiest way around it without cuting into any circuits.
Why do you want the xtra airflow in the first instance? are you having problems with overheating while 4wding? if not then why fix whats not broken. and if it is getting hot then id be looking a bit closer at the cooling system for faults.. my 2c
Yes, being auto it gets a bit hot on the beach, why not make use of an elec fan already in there? Just wired a switch in today to the compressor which when off allows power to flow thru, and when on will cut the lower and illuminate. Yet to test it, and the oil cooler, offroad on the beach - hope no more AT Oil Temp light and slightly lower engine coolant temps.
have ya had your radiator cores cleaned out, toped up the viscus fan fluid, and replaced thermostat? Im not an expert on your particular vehicle but generaly speaking no vehicle should overheat under load and if it is then it generaly is pointing to an problem of some description with the cooling system or other if diesel. If ya radiator is blocked up, no amount of air flow will cool it any better.... I would be checking out your cooling system, even over and above sussing out extra airflow. hope this helps.
Gday. Yes viscous fan fluid is topped up, radiator has been stripped and cleaned, engine has been flushed, thermostat has been replaced and drilled. The issue is the auto + the sand and big tyres= hot truck i think.
