I have a 2002 I35 and the driver's side cooling fan doesn't work. I checked the fuse and it was ok so I changed the whole cooling fan assembly. Now the driver's side fan still doesn't work even with the AC cranked up and the engine temp high.
Any help would be greatly appreciated.

 

Both fans will not come on until the A/C is on or it reaches a certain temp. Is the one fan still off when the A/C is on?

 

No, only the right fan is of when the AC is on. And when the cars temperature gets near the "hot" mark, the left fan never comes on. I don't know what to do.

 

Give me a sec. I'll look in the manual./

 

Swap the two cooling relays around thats under your hood right next to the battery, then try.

 

how about checking the fan circuit? use a test light or multimeter and see if you have power at the fan connector.

if not trace the wiring back to the fusebox checking the circuit.

power usually starts at the battery, then goes to the fuse box , then through the circuit to the load , then to ground

 

Amave, you are missing a few components, like the ECM and relays and various other sensors that control the fans.

 

Do the relays just pull out? I didn't want to force them out.

 

no because the ECM is part of the circuit....IIRC doesn't the ECM complete the path, ie ground the fans?

i might be wrong though, i'd have to look at the wiring diagram...but yeah a good way to check if his fans are working is ot " hot wire " the fan motor ( connect power and ground to see if the fans move ) that will tell him his fan motor is ok, then he can focus on either the command ( ECM ) or the circuit ( wiring )

 

i might be wrong though, i'd have to look at the wiring diagram...but yeah a good way to check if his fans are working is ot " hot wire " the fan motor ( connect power and ground to see if the fans move ) that will tell him his fan motor is ok, then he can focus on either the command ( ECM ) or the circuit ( wiring )[/quote]

I"m pretty sure the fans are good. The original fan wasn't working on the driver's side and I just put in a whole new fan assembly and it doesn't work on the driver's side either. It's unlikely that a brand new fan would be defective on the same side as the old fan.

 

I"m pretty sure the fans are good. The original fan wasn't working on the driver's side and I just put in a whole new fan assembly and it doesn't work on the driver's side either. It's unlikely that a brand new fan would be defective on the same side as the old fan.



this is the reason why i think the fan circuit somewhere might be open


i would get a wiring diagram and see where the power starts ( the diagram will tell you where the power starts and what connector(s)/wire colors are involved ) and where it is grounded....


IIRC the ECM provides the ground to complete the fan circuit depending on the inputs it receives..


so with this theory, if the ECM is trying to ground ( complete the circuit ) the fans but there is an open in the ground circuit, the fans will never turn on ...


on the same token if power is being supplied to fans but there is an open in the power side of the circuit, the fans will not turn on...



i hope this isn't confusing you

 

Thanks but that sounds like it's a little beyond my skill level. I think I'll see if I can check the relays and if that's not it, take it to a mechanic. I hate to take it to the dealer but If I can't find the solution, they dealer may just have to handle it and hijack my wallet in the process.

 

Swap Fan Relays 2 and 3. Each one of those relays control one fan's high speed.

 

Ooops, I just swaped fan relays 1 and 2. Same thing happened only passenger side fan turned on.

 

Just swaped fan 2 and 3 and it didn't work. Darn, new fans, swaped relays and the driver's side fan still won't work.
Guess I'm gonna have to let the dealer stick it to me.

 

As I look at the FSM, there is no single component (relay, fuse) that would prevent one fan from working. The fan's low speed is controlled by one group of components and the high speed is controlled by another. To my thinking, the only part that could do this is the wire harness.

Unplug the non-working fan and test it to make sure it works. When looking at the fan motor connector, hold it so the connector locking clip is on the top. The pins are numbered as follows:


** ╔═╗
╔═╩═╩═╗
║ 1 **2 ║
║***** ║ (sorry for the appearance, I don't know to do this right)
║ 3 * 4 ║
╚═════╝

To make the fan run at low speed,
ground on pin 3
12 volts on pin 2

To make the fan run on High speed,
ground on pins 4 and 3
12 volts on pins 1 and 2

If the fan runs on low speed, then the fan is not bad and the fan should run on low speed when the air conditioner is turned on.

In the wire harness itself, pin 3 is a solid black wire that goes to ground. Check this for continuity. Pin 2 is a white with red stripe wire that supplies 12 volts from fan relay # 1.

 

http://www.nicoclub.com/FSM/maxima/2002/

In the EC section of the FSM there is a long description on diagnosing fan problems. Since you've tried swapping all of the relays and fuses it's most likely an open connection somewhere. If you have the patience to follow all of the instructions in the FSM it should help find the problem - or let the mechanics do it.

One easy way to test if the fan is working is to swap the connector with the working fan and see if it goes on. Both fans should be on in park when the AC is on.

 

very good post..but in bold , do you mean complete the circuit between 4 & 3 and complete the circuit between 1 & 2?

obviously using a fused jumper wire

 

The fan motor has 2 windings inside it to make it a 2 speed motor. For low speed, just one winding is used (pins 1 & 4). The high speed winding specifically uses pins 2 & 3.

For fan high speed, both windings are used. So you have to apply ground to pins 3 and 4 at the same time and then apply 12 volts to pins 1 and 2 at the same time. If you want to jumper pins 1 & 2 together and use one wire to supply 12 volts or use 2 wires to suppy the 12 volts to each pin separately, it doesn't matter, it's your choice. If you chose to jumper the pins together, you don't need a fuse between the pins.

The same is true for the ground connection on pins 3 & 4.

 

A technician diagnosed this problem for me in about 10 minutes of looking at my car. He said the driver's side fan motor went bad and caused the Maxi Fuse overload. I replaced this fuse with $5 one from Autozone and now my fans are working again!!

Thanks to everyone who replied and I hope this helps someone with the same problem.

 

cool stuff i learned something new today ^^





glad you got the problem solved, doesn't it feel good???

 

Can someone tell me where the Maxi Fuse is located. I have the manual but it does not describe it.
Please help cause I have the same problem with the passenger side fan.

 

should be in the fusebox under the hood, check to see if the big fuses are ok ...they should be the biggest fuses under there

 

It's on the far right side near the battery. There is a box that looks similar to the regular fuse box but the fuses are larger. Try swaping the fuses around and see if the oposite fan turns on.

If you still can't find it, message me and I'll upload a picture when I get off work.

 

Passenger side fan uses underhood fuse H
Drivers side fan uses underhood fuse G

The fuses are in a box between the battery and the driver's side fender.