[plymkid]

Is there any way to test the ECU attached to the AC Blower?

My AC Blower stays on even when the key is taken out. I have read several post that say the ECU is the problem. I have removed the ECU, but visually, it looks fine with no corrosion. The part is expensive, so I was hoping I could test it before ordering a new one. Any ideas?
For info, it's a 2004 Saab 9-3 turbo diesel with dual zone auto air con.

 

[aerojon]

the controller has gone..when this happens only way to stop the fan is to remove the 40amp maxi fuse from the dash fuse box..

 

[Piper of Rose]

most likely its your fan resistor. $300 item. located on fan shroud. Plenty of posts on this.

 

[plymkid]

Thanks for the replies.

The blower did stop when I removed the fuse.

Is the controller / resistor the same thing?

I was hoping I could test the controller before ordering a new one.

One thought I had was there are 4 wires that connect to the controller. I assume 2 are the 30amp supply, and the other 2 work some sort of relay within the controller, and are fed from the ignition switch, so when the key is removed, the blower stops? Is there a way of testing these other 2 wires? Or am I wasting my time and I should just go buy a new controller?

 

[Piper of Rose]

if the resistor is bad, then most likey you have water in the fan box. There are several great treads on how to look into this. But, the resistor looks like something out of starwars. It is located bottom of the fan box next to the center of the car. Once you pull it out it will be gray in color and have spikes sticking up. If its bad there is no way to fix it. It is an epoxied resistor. 300 item to replace. Check junk yards for a replacement.

 

[aerojon]

if the resistor is bad, then most likey you have water in the fan box. There are several great treads on how to look into this. But, the resistor looks like something out of starwars. It is located bottom of the fan box next to the center of the car. Once you pull it out it will be gray in color and have spikes sticking up. If its bad there is no way to fix it. It is an epoxied resistor. 300 item to replace. Check junk yards for a replacement.

the spike like one is for the MCC,the ACC one is screwed to the bottom of the cabin fan lower housing..

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