read the whole thread before attempting to do this fix. i will not be held responsible for any damages due to in-correct work done to the vehicle.
the problem of radiator fans not comming on, for one reason or another, im guessing that the sensors and power source are good.
if you would want to just rewire the system so that it would run through switched power, and the radiator fan switch.
A better way then having a live power line running from the engine bay, into the cabin to a switch and back out to the fan, here’s the fix.
the way the radiator fan is suppost to work, is that the system has fused switched power. via ignition switch. power is then ran to one of the two wires on the Radiator Fan Switch (90-91 has it ont he back of the block, 92-93 has it on the thermostat housing) then the other wire out of the switch, would go directly to the radiator fan, then other wire out of the fan to a chassis ground.
::IMPORTANT::
-radiator fan direction - a stock radiator fan, is a puller. when the fan is on, you should feel the air in the direction pushing towards the back of the vehicle. if you would run the wires the wrong way, it will send air towards the front of the car, and will not cool down the system correctly.
-install the fuse last
-suggested to remove the negative cable from the battery to prevent any short-circuiting
i will try to draw a schmatic when i get a chance to.
The rad fan wiring is a little more involved then that, [according to the Haynes repair manual, the fan has a 12V+, [white] running from a 15A, [hot at all times] fuse in the under dash fuse box, the white wire is connected to the fans blue/black wire.
The blue wire on the fan is connected to a blue wire that runs to the “Radiator Fan Relay”, the blue wire gets a ground when the relay is on.
The coil on the “RFR”, along with the “Radiator Fan Control Module” gets 12V+, [yellow/black (black/yellow into “RFR” and yellow/white into “RFCM”]running from a 15A, [hot in run] fuse in under dash fuse box.
The “RFR” coil gets it’s ground, [to turn on] from the “Engine Coolant Temperature Switch”, [yellow/green] from “ECTS” to “RFR”.
The “ECTS” also supplies a ground to the “RFCM” the coil in the “Condensed Fan Relay” and “A/C Thermostat” and the “Engine Control Module”, through the “A/C Diode Module” [if you have A/C]
Even if a car does not have A/C , and your rewire vague, but it sounds like you are bypassing all the radiator fan controls, and supplying the fan with a switched power that would have the fan on anytime the ign. and the switch you install are on.
The radiator fan should only come on when the coolant temp is above what is preset into the “Engine Coolant Temperature Switch”.
If I am misunderstanding what you mean, please supply the wiring schematic to clear it up. :hmm: 94
the switch that i was refering to would be the coolant temperature switch, but thank you very much for the full schematic…
from the way the radiator fan works is how you explained it, according to the haynes manual, but the way im trying to set it up is to wire it up myself. and for someone would doesnt know how to trace wires from cabin fuse box, to the engine bay.
pretty much for someone who’s radiator fan doesnt work, and doesnt know what else to do. to prevent them from running live wires from the engine compartment to the cabin.
would there be a better/safer way to run a new system for the radiator fan?
using the oem specs of how the wiring should be, but renewing it, what relay to get, etc etc…
i.e.
fused constant power - to fans blue/black wire
fans blue wire - to relay (the terminal that switches a ground)
switching terminal of relay - to one end of coolant temp switch
other end of the coolant temp switch to ground
then the relay wired up correctly to send the ground to the blue wire on the fan.
The radiator fan already has 12V+ going to it, [white wire plugged into fans blue/black] and as I explained it runs from inside the car to the fan in the engine bay and is hot at all times, [so you already have a “live” wire running to the engine bay] what you are describing is replacing the oem relay with an aftermarket one, [that would assume it was the oem relay that is bad] so the safest thing to do would be to replace the oem relay.
The difference between the oem wiring and the schematic you show is the oem relay is powered by a switched power and yours is powered by a constant power, and as the only time you need the rad fan to come on is when the motor is running, the “safer way” would be the oem way, [probably why they did it that way]
With very few exceptions, the way that it was done at Acura is the best and safest way, so repairing the oem wiring and/or replacing the oem parts is by far the best and safest way.
That said, sometimes you may need a “temporary fix” in this case, [rad fan not working] and depending on why, [no power] a problem with the white wire or, [no ground] a problem with the temp. switch, rad. relay, or rad fan control module, or any of their wiring, in both cases, [as a temporary fix] I would use a 15A SPST switch to supply a ground to the blue wire on fan, or the same switch to supply the 12V+ to the blue/black, if a ground , the other side of switch would just be grounded. if for power the other side of switch would go to the 2nd ign. free pin on the fuse box, [with a 15A in-line fuse]
And as I said it would be temporary, and I would spend the time finding the problem and fixing it. 94
for a car that normally comes with a/c, but a/c is then removed, the radiator fan would not work anymore, because what? the a/c clutch runs a wire through? or what prevents the radiator fan from comming on?
that has happened to me and alot of other people, that’s why if we cant find a way to make a fix for the a/c removal causing the radiator fan to work, i would suggest to rewire the fan w/ a new relay…
but the only difference in the schematic i drew out is that the constant power would just need to be a switched power. would there be anything wrong with having it from a constant power?
i was not trying to draw out an oem schematic. just a simple drawing of how to wire it up as if there were no wires there to begin with.
my friend and I just ran it to the cd player constant 12v wire, and grounded it. I added a fuseable link. It works when the ignition is on.
I wonder if this has negative effects on the car? I know it is not as good as having it work from the factory coolant switch, but should i go back and fix this?
hardwired into the cabin with a switch isnt always the best way. it can work as a temp fix, but as time goes by, the wire will get hot, or start melting, etc etc… i’ve had that problem alot until i added a relay and with a switch inside the cabin…
i havent ran into any problems with keeping the radiator fan on, the only thing that came to mind would be that it would keep the temp low, and keep the ecu from switching from open loop, to closed loop… but then i thought about it, and now im unsure exactly at what temp. the ecu looks for until it switches… if anything, if that, it’ll just keep the car running richer then normal…
so far, other then oem setup, my setup with a relay, with the switching wires instead of running to the temp switch, is wired into the cabin to a switch… is one of the safer ways to wire it, downside to it is if you have bad memory, and forget to turn it on… or it may just be an inconvenience…
so with my setup the way it is… i will just try to keep how my setup is now, but remove the in-cabin switch, and run that wire to the temp fan switch…
FCM - the temp fan switch, when it reaches a certain temp, it just closes the loop right? i mean the two wires that are to the switch, it connects them together… is that right?
the ecu reads temps from the thermostat which then opens the thermostat and turns the fans on. the only way the car would stay in CLOSED loop would be if its like 20 degrees below zero. there is no way to keep ur car from gettin warm. even with the fans on. and with the wires melting, there is protective things out there that u can use to protect them. Not only that but if u do it right then there should be no problems with it even getting hot. If u take it up the side of the fans and up to where the hood is, there is very little heat there, plus the air blowing by would keep it cooler. All in the way u run the wires.
If you remove the A/C it should not have any effect on the rad fan, it would only effect the “Condenser Fan” and it has one of it’s 2, [blue] wires connected to a, [black] wire that goes to ground, the other blue wire is connected to a 12V+, [black/blue] wire that comes from the “Condenser Fan Relay”.
The only thing the relay that controls the rad. fan and the one that controls the condenser fan have in common is they are are both controlled by the “Engine Coolant Temperature Switch”, [supplies a ground to relay coil] the difference is, the other side of the coil in the “RFR” gets it’s 12V+ from a line, [black/yellow] off a fuse that is hot in run, [switched], the coil in the “CFR” gets it’s 12V+ from the “Radiator Fan Control Module”, [that actualy has very little to do with the rad. fan. other then both the coil on the “RFR” and the “RFCM” get 12V+ from the same fused, [yellow/black] wire, and they both get a ground from the “ECTS” although the ground for the “RFCM” is diode isolated, by the “A/C Diode module”.
Anywaaayyyyyyy… you should be able to remove the “A/C Compressor/Clutch”, "A/C Compressor Clutch Relay, condenser fan, “CFR”, “A/C Pressure Switch” and “A/C Thermostat”, and it should have no effect on the rad. fan and its operation. :whew: 94
Only the “A/C Compressor Clutch Relay” is controlled by the “Engine Control Module”, [“ECM” supplies a ground to coil in relay], other side of coil gets 12V+ from, fuse 17 7.5A, [hot in run] in under dash fuse box, "ECM also gets a diode isolated ground signal from the "Engine Coolant Temperature Switch"l but the “ECM” has no control of the rad. fan and only in a round about way does it control the condenser fan.
The temperature of the cars coolant is controlled by the coolant itself, that is what the “Thermostat” is for, when coolant gets to the “opening temperature” of the “Thermostat” it will open, it is mechanical, it has no relays or wiring, it is a temperature controlled valve.
If, and when the coolant gets hot enough the “Thermostat” will be open and coolant can flow through the rad, if the car is not moving, air is not passing through the rad, so it does not cool down the coolant, at a preset temperature the “ECTS” will close, supplying a ground to the “Radiator Fan Relay”, [so the fan comes on to draw air through the rad.] the “ECTS” is also controlled by the coolant temperature, it is mechanical, it is a temperature controlled electrical switch, the “ECM” has no control of it… :P94
Ahhhhh, no or yes, it depends what you mean by “loop” it supplies a ground, one of the wires from the switch goes to ground, and here is where you are correct, if you are talking about the “Engine Coolant Temperature Switch”, when coolant reaches a certain temperature the “ECTS” will close and connect the grounded input wire, [black] to the output wire, [yellow/green] and it will supply a ground to the “Radiator Relay”, and the other things I have mentioned, say the problem with the rad. fan is the “ECTS”, it’s not working, or it’s ground, [black] is not connected. no matter what the coolant temperature is, it can not supply the ground to the “RFR” so the rad. fan can’t come on, [the “Thermostat” will still open] you could just as well connect a small switch, [3A at most] to the output wire from the “ECTS”, [yellow/green] and ground the other side of switch, it will do the same thing, it is mechanical , a human controlled electrical switch, that will supply a ground to the “RFR”.
If the “RFR” is the problem you would have to use a bigger switch, 15A connect it as I said before to the, [blue] wire of the fan and the other side of switch to ground, or if you just want to replace the relay and the standard SPST relay pin configuration is not the same as the oem “RFR”, [and it may be] then you already have all the wiring you need for the rad. fan at the “RFR”.
Sorry guys I see no need, [except for a temporary fix] to add any wiring, relays or switches to the oem wiring for the rad. fan, the only exception would be if you added another or more powerful rad. fan, and they/it needed more then 15A of currant.
As for why cars that have had the A/C removed and the rad. fan stops working, something is being unplugged that shouldn’t be. :blah: :blah: :blah: 94
the removing a/c and radiator fan not working has happened to me, and 2 other DA’s where we removed the a/c, condensor, and fan, and the main would not work…
:shrug:
since then, 2 years ago, my radiator fan has been on a switch…
what do u think about Masterkillalw’s method of running the wires into the cabin?
and also, since my stock radiator fan stopped working correctly, i have no clue where any of the wires are… motor swap after motor swap, lhd to rhd conversion… i have no clue where these wires are anymore…
well I will tell u that I have had my fans hooked up that way for almost 2 years now. I have not had any problems other then me forgeting which postion the switch is in for them to be on.
kool… i had mine like the way you had it for a while… maybe almost a year or so? then after a while of the fan staying on, i can feel the wire near the switch, and it would be hot… i decided to run a relay to feel safer…
94