Radiator Cooling Fan Behavior

[Saabcog]

It's nice to see so many familiar users here.

I've got a questions about normal radiator cooling fan operation. I only have one 9-5 to look at, so I'm not sure what is typical for the 9-5 and what is unique.

My radiator fans rarely run as far as I can tell. I warmed the car up to normal temperature, turned on the ACC to max, let the car idle and then checked to see if the fans were running. They were not. I got into the fuse box under the hood and swapped the relay with another one. Still no fans. I removed the 20 amp fuse for the fans, checked it, and put it back in... the fans turned on. They ran for about a minute and then shut off again.

Is it normal for the fans to run so little? Shouldn't they be running most of the time?

I ask because I'm tracking down why my car is running a little hotter than normal. It's not scary hot, but it's concerning me because we're still in the 50-60 degree temps here. I can only imagine what August will be like if the car is running warm now.

I'm getting ready to flush the radiator this weekend. The thermostat was the first thing I replaced when this started and it didn't help. The fan behavior is really where I'm focusing right now. It just seems like they should run more than what I'm seeing. Any suggestions where I should be looking for issues. Where is the temp senor for these fans?

[Shazam]

When you are driving (moving) does the engine cool down? The air flowing through the grille when moving would do what the fans do when the car is stationary, so that should let you know if the fans play a role.

[Saabcog]

Correct. Driving around keeps the car at a normal temperature. It's stoplights, stop and go traffic, and those situations when it rises. It's also when the car is warm from a drive across town and I turn it off to run into the store. I come back 10 minutes later, start the car, and the water temp gauge is already above normal.

[Saabcog]

Okay, I've really studied what my fans are doing and when. Once I'm home from work I open the hood and can see that that fans aren't on at that moment. I wait about twenty seconds since putting the car in park and the fans come on. Twenty seconds later they turn off. Is this normal fan behavior for the 9-5?

[nordwulf]

I added the cooling system information to the Tutorials section. At the end of the first post for the 4-cylinder engine, there is a document you can download with a lot of information about the radiator fans and how they are supposed to work.

http://saabworld.net/f9/cooling-system-saab-9-5-a-1653/

[Saabcog]

Thanks! I've downloaded the pdf and I'm going over it carefully. My fans are not running as describe in the pdf. I'm wondering if I've lost the low fan setting. I've never heard the fans run after the car has been shut off. I've swapped out all three relays and replaced the two fuses, even though everything looked fine. It's late here, I'll see how the car behaves tomorrow.

[photousa]

Couple of things I'll just throw out. The coolant temp sensor is integral to turning the fans on and off, I've read a lot about people replacing the sensor. Also, you'll want to make that both fans are working. i was in a situation a few years about with my wife's Jetta where we burned out one fan, leaving only one working. Having only one working fan puts stress on the electrical system and can continually blow fuses.

[Saabcog]

Good idea. $15 for a new temp sensor is an easy gamble to take on getting this mystery solved. I've got my fingers crossed.

[alwaysSaab]

We use the aircon here all the time. I noticed the 2 fans are always running and they will also go into higher speed if I got stuck in slower traffic. They will revert to normal speed after a while or after the car has moved into normal cruising speed. Thus far, have not seem the fans running after the ignition is off even if the ambient temperature is high which is different from the 93SS where the fans will start running about a minute later after the engine is turned off.

[Saabcog]

Now I'm really confused. I'm convinced, having read the pdf, that my fans are working normal while the car is running. But I've never had the fan run after the car has been turned off.

That was until today.

I had a mobile device I was charging from the rear 12-volt jack in my 9-5 during my drive to work. The first time I've ever charged this thing using the car. So I get to work and have forgot about the device charging on the seat next to me. I shut off the car and two interesting things happen: The doors do not automatically unlock when the key is removed and the cooling fan is still running at low speed. I unlock the car by pressing the button and I go inside. I realize a few minutes later that I forgot to unhook the charger in the car. I go back to the parking lot and the cooling fan is still running. I unhook the charger and the fan immediately stops.
So driving home at lunch I repeated the process. I pulled into the garage, shut off the car, the doors do not unlock and the fan is running (on high this time). I unplug the charger and instantly the fan stops and the doors unlock.

What's going on here? Why is the addition charger/battery to the electrical system making the car decided to run the cooling fan and not unlock the doors? Does this help point to a reason why my car's cooling fan never runs when the car is off?