Fans not working

**Nater36** · 02-18-2011, 09:55 AM

My coolant fans do not come on at all, car creeps toward the redline and I obviously shut it off before it hits... Fans wont turn on with ac on either and compressor will not start either(idk if thats related).

**JaycenK** · 02-18-2011, 01:15 PM

Check the fuse, Check the Relays, then Spin the fans by hand (key OFF). See if the fan feels tight when it spins. If so you may have a baf fan motor. Not to bad to replace. The other thing to check is the Temp sensor in the water pump. Check on line for a how to, I know there is one out there. But this sensor sends engine temp info to the PCM and if it's bad and not sowing the correct value the PCM will never turn the fans on. You will need an Ohm meter to check it.

**Nater36** · 02-18-2011, 03:27 PM

just put in a new sensor and all three relays.. ill spin the fans though... on a better day ill run straight 12v to them see if they work i guess... what else is there?

**5.0THIS** · 02-18-2011, 03:56 PM

Could be wiring problem. Did you check for 12 volts at the fan harness plug (when the fans should be on)?

**Nater36** · 02-19-2011, 02:44 PM

havnt yet..

**Nater36** · 02-19-2011, 04:20 PM

while searching around the engine bay in the dark, i found something that has two vacuum ports and an electrical socket. None of which are plugged in. Drivers side right infront of the exhaust manifold low... Any ideas what this is?

96 formula btw

**Nater36** · 02-21-2011, 07:46 AM

update... wire from relays to computer is complete. if i ground it the fans work.

**JaycenK** · 02-22-2011, 06:25 AM

If you ground it where?

**Nater36** · 02-22-2011, 04:50 PM

if i just run a wire to it from a ground... just like in the instructions to manually wire a switch for the fans.. so the computer isnt sending a signal...

**5.0THIS** · 02-23-2011, 01:11 AM

Are you sure you dont have a wiring problem, specifically a ground problem somewhere in the circuit? Did you bust out the meter and look over everything?

**Nater36** · 02-23-2011, 03:37 PM

yep. every wire is good. i was talking to a guy with a 96 t/a and he said his fans started doing the same thing but he purchased a programmer crappertech and changed fan temps. now they work... im thinking its a problem with the computer

**JaycenK** · 02-24-2011, 08:24 PM

Reprogramming the PCM will not fix a bad PCM. So you have Ohmed out the Temp sensor in the water pump and compaired Ohm readings to what equivlant temp the ohms represent? This is what the pcm sees. Even if it's a new sensor it wont mean it's correct. You have also Ohmed out the wires that go to the PCM? Did you test voltage on the wires that come from the pcm to the fuse box? If so what readings did you get?

**Nater36** · 02-26-2011, 05:34 PM

i have confirmed no breaks in the wires from the pcm to the fuse box.. im not getting any power to them... i manually send power to that wire and the fans work... i did put the ohm meter on the sensor and heated it with a blowdryer to watch the ohms go up

**JaycenK** · 03-01-2011, 06:24 AM

[QUOTE=Nater36;2582544]i have confirmed no breaks in the wires from the pcm to the fuse box.. im not getting any power to them...

The ones from the pcm are ground triggers I belive.

**Nater36** · 03-01-2011, 06:42 AM

Yes they are ground triggers which is why I'm lead to beleive a faulty computer

**JaycenK** · 03-01-2011, 04:35 PM

But you said your powering the ground triggers and getting the fans to turn on? Do you mean grounding them? or are you talking about the possitive wire that triggers the realay?

**JaycenK** · 03-01-2011, 04:37 PM

I'm gonna go look at mine again because I wired my fans at one point to be manual and not throw a CEL then wired them back to stock when I finished my engine build and got a tune. Maybe I am forgetting something.