[MNtastic]

This odyssey has been playing out for over two months now. Tried the easy stuff first, WD-40 into the blower motor, that worked for a day. Now I've replaced the blower motor and it will work for a few seconds sometimes.
The next part is the regulator since I checked the wires again last night. Search did not come up with anyone who's had to replace both parts so I don't know if anyone else has had a similar issue.

 

[Hus_sho]

Its always better to test before replace, u couldve tested the resistor pack from beginning, really easy

 

[MNtastic]

I need a multi-meter I guess

 

[MNtastic]

Its always better to test before replace, u couldve tested the resistor pack from beginning, really easy

I do know the fan was bad. It was not turning normally, I think some rust had started.

 

[Hus_sho]

Yaa, if it was going on for a while, then it may overloaded the resistor ..

 

[foxtrapper]

Automatic climate control or manual? It makes a difference.

But, check continuity and voltage at the connectors coming into the control module or resistor pack, coming out of them, at the fan, and at ground. You're likely to find somewhere in that string a failure. The problem is either there or just upstream of it.

Yes, you really need a multi-meter, but it can be done with a test light. A cheap meter will work more easily.

Suggest also downloading the WIS for free, so you can see the wiring.

As I vaguely recall, the automatic climate control is ground switched, so the hot is constant. Not sure if this is the same with the manual climate control. With a manual climate control, it's not uncommon for an individual resistor to fail, eliminating individual fan speeds, not necessarily all of them (though it does depend on which resistor fails).

 

[MNtastic]

Yaa, if it was going on for a while, then it may overloaded the resistor ..

Yes, this is what I suspect. Ordering now before it is 0F around here next week.

 

[okcrum]

I'm confused. What is it you're referring to as the resistor pack? Is it the fan control module? Is it the potentiometer connected to the fan speed select knob in the MCC? If so, this sends the following DC voltages to the fan control module at low current. It's more likely to get dirty or wear out than burn out, since it doesn't directly drive the fan motor. It goes to an A/D input on the fan control module/regulator and that runs the motor.

0v - off
1.64V - speed 1
2.3V - speed 2
2.62V - speed 3
3.1V - speed 4
5V - speed 5

EDIT: The fan control/regulator has way too small a heatsink to be just switched power resistors, even though it's mounted in the blower output. I'm guessing it generates PWM internally to set fan speed, from the setting it gets from the MCC knob.

 

[Hus_sho]

ACC sends PWM to fan module (resistor pack), resistor pack controls fan speed through black magic 😂

 

[okcrum]

That'd be the first resistor pack I've seen with an A/D (according to WIS) and therefore a microcontroller. I've been wrong before, though.

EDIT: If it's a switched resistor pack, that would explain why they fail. That heat sink even with fan cooling is only good for about 10-15 watts of heat dissipation.

 

[MNtastic]

Power goes through it to the fan - that's what I know.
Should arrive Saturday and this will be over.

 

[okcrum]

That's not how it works, but good luck! If the fan controller doesn't solve the problem, at least you can measure the control voltage to verify the MCC module is working.

 

[MNtastic]

That's not how it works, but good luck! If the fan controller doesn't solve the problem, at least you can measure the control voltage to verify the MCC module is working.

Forum arguer?
I know this system inside and out and can provide visual proof.
It is a pain in the (literal) neck since I will have to wedge my head up the passenger foot well again.

 

[okcrum]

Nope. Believe whatever you want to if it works for you.

BTDT. The ACC motors are no easier. Again, good luck!

 

[MNtastic]

Final post

here is the new part right out of the box
Simple enough

New fan in place, new part goes under it
- notice the two wire plug going into the fan in front, those come from the resistor

Here is were it goes. Already unplugged the wire from the car here.

Old part after removal. Right plug is power in from the car, left two prongs (one black and one red) go to the fan. The plug from the car is tricky to remove because of the two plastic tabs....

Got this fine new keychain as a free gift from eSaabparts.com - thanks!

 

[MNtastic]

Final post
View attachment 270063 here is the new part right out of the box
Simple enough
View attachment 270064
New fan in place, new part goes under it
- notice the two wire plug going into the fan in front, those come from the resistor
View attachment 270065
Here is were it goes. Already unplugged the wire from the car here.
View attachment 270066
Old part after removal. Right plug is power in from the car, left two prongs (one black and one red) go to the fan. The plug from the car is tricky to remove because of the two plastic tabs....
View attachment 270067
Got this fine new keychain as a free gift from eSaabparts.com - thanks!

 

[Hus_sho]

Final post, understand its fixed 👍