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Discussion Starter #1
Hi All,
The blower fan has packed up on my parent's G 1.4. After a lot of reading on here and a fair amount of Googling I set to work to try and see if I could find anything obvious. I checked fuses, as many connectors as I could find, used my meter to check for voltages on the plug going into the blower fan (all seemed OK), looked for burned/charred wiring etc etc but all to no avail. I then got brave and decided to try and remove the fan. After a full day of removing parts - the complete dash came out - I didn't feel like I was much closer to getting to the fan.

The next step was to remove the steel frame that the dash mounts to, but when I saw that the steering column went through that frame I realised that I was right at the edge of my comfort zone and I spat my dummy.

The one thing I had read about repeatedly was the resistor pack failing. I understand that due to the extra complexity of a dual zone CC system the equivalent of the resistor pack is actually a transistor module. I have found several pictures of this module but I cannot find where it is located in the car.

So, my questions are:

1. Where I would find the transistor?
2. Is it possible to test the transistor before I go and order a new one?
3. Is there anything else I should check before I give up on it?

Any help would be much appreciated, thanks.
Paul.
 

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Usually if the resistor goes it works on full speed only and not the rest. If its not working completely then possible motor or wiring issue.
 

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Discussion Starter #3
Usually if the resistor goes it works on full speed only and not the rest. If its not working completely then possible motor or wiring issue.
Yeah, I had read that about the resistors but wondered if it was different for systems using transistors. Being a 'smart' system I wondered if it may go into a failsafe "I'm shutting down until I see and Alfa specialist" mode. In a resistor based system I presume the resistor will just drop down the voltage to slow the fan but (and I'm applying logic to Italian automotive engineering so I know I'm on shaky ground) in a transistor based system if the transistor fails there is no signal being fed back to the controller so does it then just switch itself off?? That said, I was still reading voltages on the connector going into the fan so my instinct is to look towards the fan being the guilty party.
 

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full speed usually bypasses the resistor or transistor pack. if you see voltages going in, you only need to check the ground in the same plug. if that's ok, the fan is faulty.

I'll check in e-learn about the bypass
 

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PWM control only, so if the transistor pack fails you could be without fan altogether.

however, if you get voltage to the fan, check the ground, which also goes through the transistor pack.

I can't believe the fan is that hard to reach, is it because of RHD?
 

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Discussion Starter #6
PWM control only, so if the transistor pack fails you could be without fan altogether.

however, if you get voltage to the fan, check the ground, which also goes through the transistor pack.

I can't believe the fan is that hard to reach, is it because of RHD?
Thanks for this. I get a 12v on one of the pins and a variable voltage of between 1.5v and 4v on another pin depending on the fan speed setting. I totally forgot to check the ground - d'oh!

I too cannot believe that it is that hard to get to. At one point I thought it may be easier to whip the engine out and come at it through the bulkhead! Having read some of the Fiat forums on this subject it seems that the fan on a Bravo can be replaced in under ten minutes. I love Alfas but it seems that hair loss is part of the ownership package :biglaugh:

I believe the fan unit is located right up against the bulkhead in the very centre of the car (see the red arrow in my attached pic) so I don't think it's a LHD vs RHD thing. Even with the car stripped to this point I still had to reach right in there just to touch the fan. BTW what is the strange looking piece of kit I have marked with a green arrow? It looks like it came off a WWII tank!

Cheers,
Paul.
 

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Discussion Starter #7
Did e-learn show the location of the transistor pack? If it's quick and easy to get to I may just order one and swap it out.
 

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Wow! That looks like a lot of work to get to where you are? The old way ie resistor pack just wastes energy but it its PWM then its probably more likely the controller is the problem and not the fan itself.
 

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I can't tell you how relieved I would be if it were the controller. From the attached image do you think it's likely that the blue connector I've highlighted is the controller? If that's it I may be able to get to it without too much hassle (there car is back in one piece again now as it's their only car). I'll try and have a look when I visit my parents next week.

Thanks for all the help, much appreciated.
 

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I couldn't say for sure, but it's possible. the connector has 6 wires going to it.

2 black, 1 red, 1 white/green, 1 white/grey, 1 grey/red.

1 black wire is the ground, the other black wire goes to the fan (presumably ground aswell) as does the red wire.

the grey/red is the power supply for the unit, the white/green is the feedback signal to the ac controller, the white/grey is the desired fan speed.

I think you only need to remove the side panels for the center console, similar to replace the cabin filter
 

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Discussion Starter #12
That's brilliant info, thank you so much. I will have a look when I visit them on Wednesday.

When I had the car apart I inspected that connector for bad wiring but didn't realise at the time that it may be the controller.

Cheers,
Paul.
 

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Ive seen magnesium wheels catch fire from the heat the brakes cause? Would they really build a structure that could burn in a road car?
 

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BMW's 6-cylinder engines have used magnesium-alloy blocks for well over a decade. Modern jet engines contain magnesium alloy components. A magnesium alloy should be a pretty safe choice for a structure that sits on the cabin side of the engine bay firewall.

There's still a lot of fear about magnesium: it took the FAA until last year to rescind a long-standing ban on its use in aircraft cabins: https://www.runwaygirlnetwork.com/2...o-be-used-in-aircraft-seats-as-ban-is-lifted/

...the telling part of that story is the UK company that had developed the new alloy began the approval process <i>eight years</i> previously -- technological changes take a long time to adopt in aviation. ( A previous employer once contemplated a passenger-aircraft application of its entertainment systems. It took about two meetings to realise that the approval process would take nearly a decade, so the idea was dropped. )
 
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