2004 9-5 Aero Radiator Fan Not Working

[Kazamario]

GM SW,

I've had my Aero for a little over a year and the radiator fan doesn't engage at all.
I tested it this weekend by jumping each side from the battery to the terminals and both fans engage.
Now that I know that the fans work, what do I need to replace to get them to properly engage.
I need to sort this out sooner than later, as I'm sure the excessive heat generated on idle is responsible for several failures that have occurred, which are beyond the scope of this post
Any relevant information is welcomed and greatly appreciated!

EDIT: Does anyone know what relay to change and where it's located? Since my fans do engage when jumped, I thought I'd start with any related relays.

[nordwulf]

Did you see these threads?

http://saabworld.net/showthread.php?t=1591
http://saabworld.net/showthread.php?t=1653

And everything there is to know about: Radiator fans - Saab 9-5 4-cylinder.pdf

[Kazamario]

@Nordwulf,

Thank you Sir for the info, I'll read up and report back my findings!

-M

[Kazamario]

@Nordwulf,

I read through all the information, but I'm not the best at interpreting diagrams!
What fuses and/or relays should I replace?
Can my coolant temp sensor fail and my temp gauge still work, hence my fans not engaging?
My AC pump is bypassed via short belt.

[nordwulf]

Does the temp gauge show normal operating temperature> If so, how did you determine the engine is overheating and the problem is with the fans?

[Kazamario]

Sir,

The temp gauge is operating normally, operating temp is dead in the center/middle. I don't know if the engine is overheating, however, my old BPC was really dry and brittle, and so were the hoses connected to it.
I jumped each fan from the battery to the terminals. Both worked immediately.
From what I read, as I understand it, if the fans work then it's most likely a fuse/relay/sensor.

Is that correct?
If so, I'm at a loss on which relay to check, I assume the fan fuse is labeled on the fuse panel and the only sensor that seems related is the coolant temp sensor.
Am I barking up the right tree?

-M

[nordwulf]

The fans are not always on, only when they are actually needed (like when it is really hot outside and the car is not moving. If your engine is at normal operating temperature (according tot he temp gauge), the fans won't come on.

A faulty temp sensor usually causes the temp gauge to drop all the way down. But that doesn't seem to be case. Unless you know for sure the coolant temperature is too high (this can probably be checked with Tech2), there doesn't seem to be anything wrong.

The radiator fans are also dependent on the A/C. As you bypassed the A/C, that may be a problem.

[Kazamario]

Sir,

Thank you for the clarification, I'm using my 9-3 fan engagement as a baseline.
My 9-3 also is short-belted, which is AC bypassed as well, and the fan engages very frequently.
I rarely/never hear my 9-5 fan engage, even at idle with the music off.

That's what prompted me to worry, as heat is the destroyer of all things mechanical.
Anyhow, if anything comes to mind from you or anyone else, any insight is welcomed and appreciated!

[nordwulf]

But lack of enough heat can also be bad for the engine. That's why the fans are not on all the time. And why you sometimes see trucks and cars blocking the grille to prevent too much cold air flowing through the radiator in winter time.

A Saab service center or independent mechanic with Tech2 can do a test to see if everything is working ok and can probably see any problem areas.

[Kazamario]

Thank you for your input, I really appreciate it !