Civic EG

Hey guys,

My Radiator Fan isn't turning on

I have tested the fan motor, that works
I have replaced the fan switch because that had failed
I replaced the fan fuses
I have left the motor running for 20 mins on idle, and while watching the whole time the fan didn’t turn on, an steam came from the radiator.

I have overheated a few times now, only in city driving, when I’m idling an cruising at slow speeds.

So would anyone know what could be causing this???

Thanks

Sounds like you did everything right.. Sometimes the fan won't trun on at idle, take it for a drive around the block. If it still don't come on then, My next guess would be somethings up with the wireing. You can always just wire up the fan to a switch so you can turn it on.

turn your car on, crank the heat way up, that will cause the engine to warm up quicker and force the fan to come on, what does your thermostat on the gauge say? maybe you have a bad thermostat, ecu doesn't know that it is at the right temp yet, so fan doesn't turn on.

Could be your t-stat sensor or your t-stat is always closed.

wnos100shot wrote:Sounds like you did everything right.. Sometimes the fan won't trun on at idle, take it for a drive around the block. If it still don't come on then, My next guess would be somethings up with the wireing. You can always just wire up the fan to a switch so you can turn it on.

I might take it for a drive then since i replaced the fan switch.

Method wrote:turn your car on, crank the heat way up, that will cause the engine to warm up quicker and force the fan to come on, what does your thermostat on the gauge say? maybe you have a bad thermostat, ecu doesn't know that it is at the right temp yet, so fan doesn't turn on.

Don't have a/c, btw i thought that if you crank your heat up that is suppose to cool the engine down?

the temperature guage is usually just below half, until i leave it idling in traffic for a while it starts to overheat.

MG6 wrote:Could be your t-stat sensor or your t-stat is always closed.

Where is the thermostat sensor?, and how do i check if my thermostat is broken/failed?

On your thermostat housing, there is a 2-wire plug. That one controlls the fan. You can unplug it, stick a jumper wire in and leave your fan running. Then anytime the key is on, the fan is running. I have done this many times with zero problems.

flyinryan122 wrote:On your thermostat housing, there is a 2-wire plug. That one controlls the fan. You can unplug it, stick a jumper wire in and leave your fan running. Then anytime the key is on, the fan is running. I have done this many times with zero problems.

I can't find the part image on the Honda Part site, but i do have the part #37760-P00-004 (might be old part number), this will be the switch.

**Update** found the image
http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=CIVIC&catcgry2=1993&catcgry3=3DR+DX&catcgry4=KL4AT&catcgry5=ENGINE+SUB+CORD+-+CLAMP

#16 is what you want switch, and #17 is the sensor.

It's right there one the thermo housing. #5. right below where the arrow from 14 is going, This pic is from the firewall side

Thats the fan switch right? That is the only two wire plug on the thermo housing.

I went to my mechanic see if he would know, I asked if it could be the thermostat, he said when it starts overheating check if the fan is turning on, if not there is a problem with the fan, so i did that an the fan still didnt turn on.

So must be an electrical problem, im taking it into the 3rd auto electrician to have a look the other two didn't have a clue an one even had a eg wit a b16 (same setup as me) an still didnt know

flyinryan do you mean leaving your fan running full time? wouldn't that be a big electrical drain?

si-b16 wrote:Thats the fan switch right? That is the only two wire plug on the thermo housing.

I went to my mechanic see if he would know, I asked if it could be the thermostat, he said when it starts overheating check if the fan is turning on, if not there is a problem with the fan, so i did that an the fan still didnt turn on.

So must be an electrical problem, im taking it into the 3rd auto electrician to have a look the other two didn't have a clue an one even had a eg wit a b16 (same setup as me) an still didnt know

flyinryan do you mean leaving your fan running full time? wouldn't that be a big electrical drain?

Thats the one you've replaced?

Only time it would be a drain is if you had the key on, but the engine off. But even then, it isn't bad. This is how we run our race cars. Fans on at all times, and key on but engine off while in the staging lanes or pits.

Yep i replaced the fan switch.

Don't really want to leave it on all the time, hopefully i can figure out the problem an fix it, otherwise i will have to do what you suggested, thanks heaps you've been a great help

anymore suggestions on how to fix this will be greatly appreciated

Do you have a chipped ECU? It can be changed through the ecu if it's chipped. Thats another way you can check the fan circut

No i don't, it's a stock b16a ecu

I would not leave the fan running on all the time for your daily driving. Your engine will never run right and you will have poor gas mileage.

Yep that's true...