The fan in my EG hatch won't turn on. It works with the fan switch jumped so I replaced it even though I had a mishimoto less than a year old in it, anyway still doesn't work, but runs with the fan switch jumped. No blown fuses, and the relay under the hood is fine, any ideas on what it could be?

 

Which Mishimoto product do you have installed on the car? Your post is a little confusing.

If any of our products have issues for any reason, please contact us either via PM, phone, or e-mail.

 

Perhaps the engine did not get hot enough to trigger the switch. Otherwise, bleed the cooling system and make sure the thermostat is not stuck open.

 

I had a mishimoto fan switch. I bled the coolant and the thermostat opens, I can't figure out whats wrong.

 

Bump. Any ideas anyone?

 

Bump for help. IDK if its related but the condenser fan has the same problem. It will only spin when hooked up to a battery. I read that both fans should come on with the a/c button on, anyone know if this is true?

 

Have you checked for a short in the wiring? Also, try and re-install the stock fan switch and see if that helps any more. If our fan switch is the culprit, PM me.

 

BUMP. I don't think there would be a short since the fan switch plug runs when jumped. Anyone know what else to check? I don't have the stock switch anymore.

 

Now the fan does not turn on 24/7, only if the temp is within the hot temperature range, and do your car over heat?

If you jump the switch, fan it kicks on, then it's your switch.
Anyways check your relays for defects.

 

It over heats at idle. It turns on when jumped, but both the brand new fan switch and the old mishimoto don't work. The relay works, its the same as the power window relay and it works with the power windows.

 

Anyone? Been through two fan switches, neither work. Where else should I check?

 

check the engine coolant temp switch. should be in the front of the block. and try a new different fan switch and id imagine you could get some warranty after that little time from mishi.

 

Just changed the coolant temp switch too. I guess I'll talk to mishimoto

 

you bleed the system after each time doing these things right? just makin sure.

 

make sure the plug have a good connection with the switch.

 

Yeah I've bled each time, Although Honda says wait the fan to run twice, I obviously can't in my case. The plug is securely connected to the switch.

 

i have the same problem..i was told it might be the fan switch..

 

This might sound dumb but have you checked the fuses?

 

you are missing a big part of your statment, the circut is real simple. you have a controled side which has 12v and the fan then you have the controller side of the relay which has 12v and then the fan switch that goes to ground. if I jumper the fan switch and the fan comes on then I have pretty much diagnoised the whole circut. I know one that both of my 12v pins are hot at the relay, I know that the wiring from the realy to the fan is good, I know the relay is good, I know that the wire from the fan switch to the relay is good and I know that the ground from the block to the fan switch is good. you have pretty much got it down to a fan switch but a couple of things to consider is actually getting a temp gun and measuring the temp at the fan switch and then also at the temp sensor at the same time. you could have air in the sys but you say you have bled it several times or you could have a blown headgasket which could super heat the water close to the temp sensor and not the fan switch. also another thing to consider while measuring the temp in several different places is to determine if the temp sensor is even right or accurate. next step is to get a temp gun. if you want to check your fan switch then monitor the fan switch temp with the temp gun then check continuity across the two pins with a ohm meter. good luck

 

Thank you for your informative reply. I will work on it. I guess I will try bleeding again. I just put in an after market temp gauge and it reads 190 when driving this should be hot enough to trigger the fan right?

 

I dont know about the mishomoto one but most fan switchs come on around 208 if I am not mistaken. if your after market gauge reads 190 then i suggest montoring that gauge untill the fan comes on or the gauge goes over 215. at that point you can easily say that there is a problem with the fan switch either it cant see the same temp as the temp sensor or the switch is bad. good luck man

 

Check how hot your lower rad hose is compared to your upper hose. If it feels cooler then the top hose, my money is on a faulty thermostat.

I just had the same problem a few weeks ago. I thought it was my fan, but it also came on when i ran direct power to it. Changed the thermostat and I haven't had any problems since.

 

it look like it should come on at 203, I get up to 200 when I'm at idle I'll let it run a bit more.

 

Got up to 230 and no fan, I'll try what was suggested and if all else fails a third fan switch

 

Before you do anything, try to do a pressure test on your system, there may be a small leak somewhere. Mostly the Rad