Thermo Fan turning on from cold start

[trd_st184]

Hi Toymods,
I have been having some trouble with the thermo fans on a AE92 corolla. The fan will come on under cold start and won't switch off.

I replaced the radiator fan switch with a brand new one but the fan is still coming on. The motor is a 4age 16v small port

I was wondering if there was a fan relay that could be causing an issue or anything else I could check/replace. I did try swap over the relay with another one but it still seems to be doing the issue too

Thanks in advance,

[lexsmaz]

I'm guessing you mean it comes on with a cold motor & if that's the case as you said it could be a faulty relay ..

[trd_st184]

I'm guessing you mean it comes on with a cold motor & if that's the case as you said it could be a faulty relay ..

Sorry thats right, it comes on with a cold motor. I tried replacing the relay with another one and it does the same thing unfortunately. I can hear the relay switching on straight away the second the key is turned onto ignition so it makes me think there might be another issue somewhere else.

Could someone have hard wired the relay to turn with the ignition? I found a blue wire which has been earthed to the battery using a lug but I can't for the life of me figure out what its for. The whole body loom, engine and engine loom have been swapped from a corolla sx into an ae92.

[lexsmaz]

If its a conversion as you said it could be anything, try disconnecting that blue wire you talk about, but first see if the fans come on with ignition on & if so no need to start the car & just disconnect the blue wire turn on the ignition & see what happens with the fan ..

Also from memory the fan switch that you replaced are wired up to a circuit opening relay in that if you disconnect the switch the fan runs all the time so it could be a broken earth to the switch or from the switch to the relay, I think I'm correct on broken earth wire can cause the fan to run all the time, someone else might weigh in there ..

[fixeruperer]

dont the fans come on sometimes, when there is an ecu error code ?

[Adubwub]

Youll have to check the wiring. This thread may help
http://www.toymods.org.au/forums/tec...hermofans.html

Check the switchs earth. Its earthed through the thermostat onto the gearbox.

[dumbass]

sounds like its your ac that is the issue
u need to bypass something if its a conversion

[trd_st184]

Thanks for the suggestions everyone. So far my air conditioning is still disconnected (including the a/c fan) so this could contribute.

I was reading an article and it did mention the a/c pressure switch also controls when the fans turn on and off. I don't think I have any a/c pressure switches plugged in (a/c compressor is actually unplugged at the moment).

Any of these could be contributing enough to keep the fan on? Will have to check again tonight.