My A/C works great, actually gets pretty cold while driving down the road. If im sitting in traffic its still cold but not like it should I don't think. Ive sprayed out the radiator/condenser area, my question is... should both of my fans come on when the a/c is turned on, the fan on the pass. side is the only one that comes on..

 

Yes, both should be on when the ac is running.

 

thanks NJ.. that's prob why its not cooling as good when stopped. I guess the best way to test it is to run 12v directly to the fan ??

 

That will make it constantly on. Check all if the connections first. The motor to it may be dead, which if thats the case, 12V wont turn it on anyways. It would be a good way to check the motor though.


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well... I noticed both electrical connectors for the fans are the same so I plugged up the
the one from the pass side fan to the drivers side and the fan came on so I know the fan motor is working. Does anyone know what signals the drivers side fan to come on with a/c on ?

Does the drivers side fan come on at a certain temp (overheating) or what ? That worries more than anything I don't wanna get stuck in traffic and have an issue. I purchased the car this past fall so this will be the first time ive had it in the summer..

 

Both fans come on at the same time. I would think there is a fuse somewhere for it. Have you searched to see if anyone else has had this problem? I would, but I can't search on the app. Lol.


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LOL.. not at the same time.. I unplugged the pass side fan and used that plug to power the drivers side and it came on.

Update.... I messed with the plug on the drivers side fan and it started working but it runs for about 15 sec shuts off.. then about 30 sec later comes back on and keeps doing this. Basically it keeps cycling, the pass side fan stays running constantly. So.. im guessing whatever activates the fan is causing it to cycle or a bad relay ??

 

But if you moved the wire and was able to get it to come back on, I don't think a relay would really do anything. Have you cleaned the clips? It could be a dirty connection. Or a break in the wire.


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Does the passenger side fan ever turn off? Or does it start as soon as the car is turned on?


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yes.. the pass side fan seems to be working fine. When the A/C is on the pass side fan runs constantly. I tried swapping relays and the drivers side fan still cycles on and off, pass side fan runs constantly. I can hear the relay click for the drivers side fan so whatever signals it too come on and off is the problem. I don't know if the A/C switch is causing the problem or what. Ive cleaned the connections. Its something that suppose to signal the fan to come on and stay on...

 

http://www.nicoclub.com/FSM/Maxima/1997/

^^ check your 97 FSM, section LC, page LC15 http://www.nicoclub.com/FSM/Maxima/1997/LC.pdf

and section EC, page EC340
http://www.nicoclub.com/FSM/Maxima/1997/EC.pdf


happy reading

 

That's really confusing. It's past what I can think of. I'm not sure what else could cause it to not work right. :\


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looks like I got some reading to do LOL... ill keep yall posted

 

There's 3 relays I think. 1 for each fan for LOW, and 1 for both fans on HIGH. I think.

 

gotcha... I only checked two relays ill check the third.

 

The a/c compressor works best at higher rpm's. When the engine is idling, the compressor is not running at it's best efficiency, so the passenger cabin will warm up a little.

You had a 50/50 chance and Murphy's Law got ya. Actually it is the reverse.

Fan Relay #1 is for low speed on both fans. Fan Relay 2 is for high speed on the drivers side fan and Fan Relay 3 is for high speed on the passenger side fan.

In case anyone cares...

When things are working properly:

When you start the car and the engine is cold and the air conditioning is OFF, fans do not run. When the engine temperature reaches 200 degrees, both fans run at low speed. When engine temperature reaches 220 degrees, both fans run at high speed.

When you start the car cold and you turn the air conditioning ON, both fans run at low speed. When the engine temperature reaches 200 degrees, both fans run at high speed.

Pin 14 of the ECM goes to 0 volts, activating Fan Relay 1 which sends 12 volts to pin 1 of both fan motors, the low speed winding. Pin 4 of the motor is connected to ground.

Pin 13 of the ECM goes to 0 volts, activating Fan Relays 2 and 3. Fan Relay 2 controls fan motor 1, while Fan Relay 3 controls fan motor 2. The fan relays send 12 volts to pin 2 of the fan motor, the high speed winding. The fan relays also connect the fan motor pin 3 to ground.

On the fan motor wire harness connector: (4th gen colors)
pin 1 is a white with black stripe wire - low speed 12 volts
pin 4 is a black wire - low speed ground.
pin 2 is a white with blue stripe wire - high speed 12 volts.
pin 3 is a white with red stripe wire - high speed ground.

The ECM uses a water temperature sensor in the engine to determine when to turn on the fans. Also note that there are 2 water temperature sensors in the engine, one for the ECM and one for the dash gauge.

Dashboard fuse 17 powers the energizing coil of all 3 relays.
Underhood fuse D powers both fan motors at low speed.
Underhood fuse E powers both fan motors at high speed.

-=*=-

 

thanks for the explanation Dennis... Without making it confusing... my pass side fan works low and high speed. As soon as I turn the A/C on the pass side fan comes on and stays on. My drivers side fan is cycling on and off. Whatever.. is telling that fan to turn on is my problem. I can hear the relay for the fan clicking the fan on and off and I checked the plug for current and its intermittent, its not getting a constant 12volts like the pass side is. It seems to be working on high speed though ( drivers side fan ).

In short.. Whatever tells that fan ( driver side ) to come on and stay on is faulty or.. the low speed side of the fan is faulty, I don't think that's the problem because after it ran and shut off, I pulled the plug from the fan motor and there was no current going to it, wait for about 30 sec.. then the relay clicks and I get power to it for about another 30 sec and so on.

 

You can try swapping the high speed cooling fan relays and see if the problem changes to the other fan. They are in front of the battery, RAD FAN 2 and RAD FAN 3.

Because the electrical contacts inside the relays have different configurations, only swap a relay with one that is the same color.

 

ill give it a try.. thanks dennis