Hello I have a 08 g37s so I'm having pronlems with my fans, the car drives good and all, but when I turn on my A/C the fans turn on and blows cold air as it should, but as soon as i come to a stop it slowly starts blowing hot air and the temperature starts to go up, as soon as I start moving A/C starts to blow cold again and tenperature regulates again, so what could be the problem? if my fans do turn on i know they work but as soon as i stop they turn off? has anyone had a similar problem? could it be a relay or wiring? ( was in an accident months ago had to replace radiator, fans, reservoir etc)

 

Fan switch seems to be bad or voltage regulator

 

Sorry to ask but where is the Fan switch? is it like a relay or is it in the actual Fan?

 

You mention you were in a accident and had several parts replaced. Was this work performed by a reputable shop? I ask, only because there might/should be a warranty in place for repair work. Might want to check on that before beginning any diagnostic work as it could be any number of issues: fans, fan control module, wiring/harness, various sensors, etc...

In my case, and with the same symptoms, the IPDM/er test showed both fans were giving up the ghost. Easy fix for me.

I would first check for a warranty on those previous repairs. Then you can navigate your next move.

 

Hello, so basically i bought some parts new and some used, fans were new, they were installed by a body shop kot a mechanic shop, Is there a module, sensor, fuse that tells the fans when to turn on and off? if so which one is it? because like i said they only seem to get turned off when i come to a conplete stop and once i start rolling again they come on again, they way i can twell they turn on and off is because the a/c blows cold air while rolling and starts blowing hot air and overheating when i stop so i guess it must be a sensor for that.

 

All that is involved:


The FAN CONTROL MODULE is the silver box mounted between your two fans. The easiest way to check if the fan module is good is to perform the IPDM/er self-test:



In my case, while driving, once I came to a stop the temp gauge would rise and the AC would not blow as cold- both as a result of poor airflow across the radiator/ condenser. Once I began moving everything went back to normal. I ran the test and both of my fans were barely running at all. This test will run your fans at 50% and then at 100%- you can tell the difference. If both work as they should, the module is fine. Then you have to look elsewhere.

You may want to download a copy of the FSM for your car. It will help you to diagnose further.
2008 G37 Coupe FSM

 

Thanks a lot man I hope this helps, yesterday i realized that the fans start turning on and off once the temperature reaches the halfway point so i think it might be a sensor or something that tells the fans when to turn on and off, I'll see into that, thanks again bro

 

So i ran the test and both my fans barely turn on for 1 second and turn right back off so with this test i can assume my fan control module isn't working? in this case do you replace the whole fan itself or just the module? what did you have to replace in your case it sounds almost if not the same issue as mine, thanks again dude

 

Relay first

 

I've been truing to find the relay and all i found was de 50 fuse, I cant find the relay for the rad fan

 

The PWM Relay is for the cooling fan. PWM= Pulse Width Modulation, which controls fan speeds.

Did you run the self test?

 

Oh ok I didnt know that was it, I was looking for Rad Fan 1 2, but if it was the relay wouldn't they not turn on at all?

 

If the relay is shot, the fan module won't get the signal to turn the fans on/duty cycle. This is why the self test is important- if the fans come on and cycle as they should, you can eliminate the fans, module, relay, fuses from the equation.

The fans might come on, but do they run at FULL speed?

 

No, I did the test and they BARELY come on for 1 second and they turn back off, it happened all 3 times.

 

Then likely your fans are shot.

Another test you can do to confirm if the fan motor/s are done and IF you have another 12V battery available (I used the one from my tractor): I briefly connected each fan directly to the battery to see if it ran at full speed. In my case they didn't. If yours run full speed then you can go from there.