Radiator Fan Mayhem

[Tailfin]

Ok, the thing just won't work. I have replaced the cooling fan switch on the radiator, the relay, the fan motor itself (which I have tested and it works directly connected to the battery)...and the dumb thing still won't kick on and the engine will eventually overheat if it's taxed at all. I looked at fuses...there was one under the dash that said cooling fan, and one under the hood in the box as well, both looked fine. Anyone know if there's anything else to check, or does that just leave the wiring in between which is outright ridiculous to trace? :sad2:

Also, if I'm to just hard-wire it, I'd love suggestions on the best thing to wire it to...and where those wires are on an 88 LX...as I'm new to this breed of car.

[ghettogeddy]

here is a thread that was started and ended today just read my post on how to wire them to a switch its very easy
and please next time search its your friend and will open the doors to all the answers well not all of them
http://www.3geez.com/forum/showthread.php?t=54708

['89AccordLX(Rus)]

Ok, the thing just won't work. I have replaced the cooling fan switch on the radiator, the relay, the fan motor itself (which I have tested and it works directly connected to the battery)...and the dumb thing still won't kick on and the engine will eventually overheat if it's taxed at all. I looked at fuses...there was one under the dash that said cooling fan, and one under the hood in the box as well, both looked fine. Anyone know if there's anything else to check, or does that just leave the wiring in between which is outright ridiculous to trace? :sad2:

Also, if I'm to just hard-wire it, I'd love suggestions on the best thing to wire it to...and where those wires are on an 88 LX...as I'm new to this breed of car.

Have you tested for power at the radiator temperature sensor? Have you tried jumping the pins? It is not unheard of to have a non-functioning switch even if it is brand new. Get a multimeter and check the circuit for power. It should be hot whenever the ignition key is in the ON position. HTH

[bobafett]

if u have an efi car u can jump the sensor at the bottom of the radiator and it should cause the fan to come on, like he posted above. i chose to run a switch to this sensor (which is now unplugged) and i have a switch on my console that controls the fan operation. as long as the ignition power is on, my switch will control the fan. i usually just leave it on all the time once the car is warmed up. i would rather replace a warn out fan more often than have my engine overheating on me. :)

i am willing to be if you spliced into the sensor i am talking about, instead of just unplugging it and jumping/switching it, you would be able to retain stock temperature controlled fan operation as well, but you would basically have a manual fan override control. however since ur fan is not coming on properly, i would just unplug the sensor, and wire it up to a switch. :) good luck

['89AccordLX(Rus)]

You can jump the sensor on either the carb or the EFI engines. The basic principle behind the sensor's operation is the same.

[stat1K]

i just wired a switch to run it all the time as i live in arizona and it's hot as shit! that's my suggestion.

[Tailfin]

Thanks for the help all. Ghettogeddy, just so you know, I did notice that very thread before when I looked, but it didn't asnwer a primary concern I put in this one, which was possible good locations to steal 12V from, like the ignition, so this way, the fans would just turn on whenever the car was on....though...I did not make that perfectly clear so sorry about that lol. I don't mind the switch, which I might end up doing direct from the battery, but this car isn't for me, and I just didn't want the possibility there of spacing out, temp going up, and forgetting the fans.

I don't understand how you "jump" the switch on the bottom of the radiator... It's just a piece of metal that screws in so the coolant will run over it, and I presume has a diaphram inside that moves up and makes contact inside, which is not something I have access to. Both the upper and lower hoses were hot, so the problem is not a cooling system plug/not letting the coolant get to the sensor (it's a new radiator anyhoo).

I should probably just go from the battery anyway, since the fans draw a good chunk of current.

The other reason I was thinking of just having them kick on with the car is I really don't understand why it would make all that much difference. The thermostat should be keeping the coolant just in the engine until it gets up to temperature, so when it lets it out into the radiator, etc..., I would think it would just cool it faster, or have a slightly lower temperature that it levels off at, which could be compensated by getting the warmer thermostat.

Anyway, I might just end up doing the switch thing (how ghetto :rolleyes: ). I've been tearing my hair out re-routing vacuum lines to get the carburetor to work on this thing for a week as is, so trying to find all the fan wires isn't sounding fun... Cooling fans really should be belt-driven :uh:

['89AccordLX(Rus)]

Jumping the switch means taking a paper clip and connecting the two terminals in the plug connecting to the switch. This simulates the switch closing, and thus would indicate whether the issue is with the switch or somewhere else.

[Tailfin]

Yeah I know what jumping is, but I wouldn't want to try that and plug it in since it would touch the terminals in the fan plug as well, hot-wiring it. Hmm, though I agree it's good to test for power with a multimeter... Sorry, I was just thinking inside the box :-P.

[Oldblueaccord]

Ok, the thing just won't work. I have replaced the cooling fan switch on the radiator, the relay, the fan motor itself (which I have tested and it works directly connected to the battery)...and the dumb thing still won't kick on and the engine will eventually overheat if it's taxed at all. I looked at fuses...there was one under the dash that said cooling fan, and one under the hood in the box as well, both looked fine. Anyone know if there's anything else to check, or does that just leave the wiring in between which is outright ridiculous to trace? :sad2:

Also, if I'm to just hard-wire it, I'd love suggestions on the best thing to wire it to...and where those wires are on an 88 LX...as I'm new to this breed of car.

Only thing that I can add is that my cars fan rarely if ever comes on when driving unless im up over 2500' . So i would be looking at whats going on with your cooling system.

If you have AC turning it on should force one if not both of the fans on even if that AC dont work. You can pull the 10 amp fuse as well if you dont want it on but the fans will still come on.

wp

['89AccordLX(Rus)]

Yeah I know what jumping is, but I wouldn't want to try that and plug it in since it would touch the terminals in the fan plug as well, hot-wiring it. Hmm, though I agree it's good to test for power with a multimeter... Sorry, I was just thinking inside the box :-P.

You don't need to plug it back in. Here's the procedure:

1) Disconnect the harness plug from the coolant temperature switch.
2) Turn ignition to ON
3) Use a paperclip or wire to bridge the two contacts inside the harness plug.

I'm not sure what you find dangerous about this. Its a 2 minute test :)
If the fans come on, the switch is shot. If not, break out the multimeter or hot wire it through a switch (I'd rather fix it properly :)). Best regards.

[Tailfin]

Oops...yes, I forgot that the switch is a separate plug from the direct power to the fans...geez lol... Yeah, I'm the type to want it fixed properly as well, but I have a feeling it's in the wires somewhere since I've replaced everything... And if I have a brand new, defective part, I'll...I'll...I don't know, but I'll do something... Also, with that jumper test, it certainly does help narrow down the problem, but it could also be the wiring to the plug.

['89AccordLX(Rus)]

Oops...yes, I forgot that the switch is a separate plug from the direct power to the fans...geez lol... Yeah, I'm the type to want it fixed properly as well, but I have a feeling it's in the wires somewhere since I've replaced everything... And if I have a brand new, defective part, I'll...I'll...I don't know, but I'll do something... Also, with that jumper test, it certainly does help narrow down the problem, but it could also be the wiring to the plug.

I've been a member here for about 4 years and have seen many people report issues with brand new coolant temperature switches. Some aftermarket parts are just poor in quality or lacking in quality control. The OEM switches work for a very long time. I guess Honda's quality standards have something to do with that. Hope you can figure this out.

[ghettogeddy]

ya i would have to say i never here my fan come on my car is ulwas under the halfway mark, i have a new water pump, thermistat, and a koyo rad

[Difranco]

I am having the same problem with my 86 accord. The Fan works fine when I bypass the thermoswitch.

So I have replaced the thermoswitch, 2 times both new parts from two different auto parts chains and made by different manufacturers, but still I cannot get these fans to turn on unless I bypass the switch.

[Tailfin]

Well this is worth updating... I've had 3 sensors in this thing in all. I found out if I jumper it with a paper clip, the fans work. So I ordered the Honda sensor from www.hondaautomotiveparts.com , no cheaping out this time...and it still didn't work. So these fans are going to run whenever the car does...and the designer of them shall hang for high treason or something...