rd2tibb

Hey guys, my poor Tib is trying to overheat now that the temperature outside is getting warmer, and I notice that my rad. fan is not turning on when the car is obviously overheating. The temp guage got to about 3/4 once and the rad fan and the AC fan still werent running!



So I did some research here. I checked the under-hood relays and they are fine (are there other fan-related fuses somewhere?)



I turned the A/C on because apparently that forces both the A/C fan and the Rad fan to turn on, but neither of them ever do. Once the A/C fan came on, but the Rad fan was still dead.



What can I do next? I hear that if I disconnect the coolant temp sensor the car should panic and turn both fans on, is this a good idea?



Can I just wire both fans straight to the battery for now until I figure out the problem?



Thanks!

alice6

i'd test the fans and make sure they work. use jumper wires and wire it straight to the battery. if it doesn't turn on, tap the motor with a wrench, if that turns it on you need a new fan. you can also check to see if voltage is getting to the fans when the car is hot.

rd2tibb

Ok I took jumper wires to the fans and it appears that the AC fan is dead. But that doesn't explain why the Radiator Fan does not turn on when the car is overheating? Are the fans wired in series?

majik

wait... you said that both fans DO turn on when you turn the A/C on, right? So the fan isn't dead.

You can't wire them straight to the battery, that will cause them to run constantly, even with the car off. It could be that the temp sensor is bad.



1. Is there coolant/water in the radiator? In the reservoir?

2. Is the radiator cold or hot when the engine is overheating?

3. When the car is overheating, are you able to do anything to bring the temps down, such as turning on the heat?

4. Does activating both fans cool the car down?

5. Does it overheat when idle, driving, after driving and then coming to a stop?

HotBlue02

I forgot to plug in the a/c condensor fan once and this caused me to overheat cause the radiator fan didnt turn on. So if you condensor fan is dead then that makes sense that the radiator fan is not turning on.

rd2tibb

Wow thanks for the response!



@majik -

The fans do not turn on when the AC is on, only sometimes the AC fan will turn on when the AC is on, but never the rad fan. I will try to unplug the coolant temp sensor and see what happens, I have read on the newer Tiburons this causes the ECU to panic and run both fans. I guess it can't hurt at this point!



1. Coolant level is fine and it was flushed pretty recently, roughly a year ago. I'm not sure if its circulating properly though how do I test that?

2. Oh, very good question I will test that next time the car overheats. I only thought to check out the fans, never the rad!

3. Yes, if I turn on the heat inside of the car the temp goes right back to normal within 5 seconds or so. So I am not too worried for now, but as it gets hotter outside I'm afraid this method will not work as well

4. This is also a good question, I will need to let the car idle long enough to overheat a bit and then manually wire the fans to the battery and see what happens

5. The car cools down once I am at speed. When idling, it slowly overheats. When in stop-and-go traffic, it heats up very quickly but turning on the heat in the car brings it back to normal very quickly



@HotBlue02 -

Ok, maybe my best bet is to replace the AC condenser fan since it seems to be dead anyways (doesnt spin when wired to battery). However, I have recently seen this fan spin when the AC is on, but the rad fan was not spinning. I think I could have a wiring/short circuit issue as well?



Well I will need to do some testing on Saturday, I promise I will keep you guys updated. This is an awesome community and thanks for the warm welcome

faithofadragon

....ok so does the a/c fan work or not



you said it works when the a/c is turned on



then you said it doesnt



which one is it

HotBlue02

if it did not fire up when direct power was applied id say its toast.

rd2tibb

Ok guys, I've done some more testing and here's what I've found:



Both fans spin. The rad fan will turn if hooked up manually to the battery, and the AC fan might (I had trouble getting a good connection) but the AC fan turns on when the AC is turned on (sometimes?) and even when the AC is not turned on (i guess to cool the car off?)



Last week, the car was close to the red on the temp guage. I popped the hood and neither fan was on. I turned on the heat inside the car to get the temps back to normal.



Today, I took the car for a drive to get it up to running temp and was a little more aggressive than usual with the throttle. The car would not overheat no matter what I tried. When I popped the hood, the AC fan was on, even though the AC inside of the car was turned off. But the rad fan was off. I guess the AC fan turned on to cool the car down, but why didn't the Rad Fan? Does it turn on at higher temperatures?



So now I'm not sure what to do. Both fans spin, just not when they are supposed to and not every time. I guess I have a short somewhere? What should I do next?

HotBlue02

Well the A/C fan still sounds iffy to me, it should fire everytime its giving direct power. Send a ground right from the battery -post through the a/c fan relay (remove relay) port number 2 using a jumper wire. If u look at the schematic you see that the condensor fan has power at all times, the relay just allows the ground through. Do the same for the radiator fan but with +post to port 2 rad fan relay to make sure both are working perfect.





If those fans pass the tests then you might want to check continuity for all the wires, I would start with ground. If your not sure how then ask, were here to help.