Cooling fan resistors and torx request, C4S

[toastyhamster]

Spent a couple of hours trawling through forums to find the answer to this, so apologies if this is a repeat but I can't find the answer.
My front end is in bits to replace the rads/air con condensers, while it's off I've tested the fans via jumping the relays and the drivers side resistor is bad.

The C4S/Turbo uses a different resistor to the standard 996 or 986, it is mounted on the back of the fan and has 4 wires in total going to three terminals on the OEM resistor. If I buy an off the shelf 100w 0.5ohm resistor from a component shop how do I wire it in? I understand that one of the wires may be unused as the turbo has a "medium" fan speed option which I don't need.

2 x Yellow/Black wire on one resistor terminal
1 x Yellow/Grey on one terminal
1 x Yellow/Blue on one terminal

My guess is the 2 Yellow/Blacks on one end of the resistor and one of the other two on the other end?

Also, related, all the fasteners were rusted in, anybody know where I can get the Torx head self tappers that the air con condensers are held on with? Annoyingly they're not on the parts diagram and OPC's are closed. Design911 drew a blank unless I can send them a picture.
Thanks

 

[kurlykris]

On this photo, resistor goes between green and white wires. Basically you have a +12v green wire from high speed relay to motor, +12v white wire from low speed relay to motor and a black -12v wire to the motor. Low speed white +12v is dropped to +6v by the resistor to run at half voltage.
Hope this helps :thumb:

 

[toastyhamster]

I wish it did, that's not the C4S/Turbo setup. I only have two wires going to the fan motor, one ground, one other.

 

[deMort]

Hopefully the below diagram will help ..

 

[kurlykris]

Demort beat me to it, but I found the Turbo schematics online. There are indeed 3 speeds on the Turbo, but you don`t need the middle speed, so you need 2x yellow/black to one end of your new resistor and yellow/blue to the other end, ignore the yellow/green( grey?) as this is for middle speed :thumb:

 

[toastyhamster]

Perfect, thanks, will get the resistors ordered and give it a go.

 

[Steve B]

Please can you report back as to whether it works as I also have resistors that are showing their age on my C4S! :thumb:

 

[Ghianightmare]

Having a similar issue myself

Fan dead when i put 12V directly on to it. Ballast disintegrated when I tried to remove the 12v Feed spade :nooo:

New fan for the C4S/Turbo seem to be twice the price of other fans but at least I know I can use the same ballast that has been successfully used by others here and that I don't have to fork out £140.

Thanks

 

[diverzeusy]

I just had this on my turbo, So, i carefully removed the back off the fan and discovered that it was full of dust and the brushes were worn fully down and lost contact.
so I had an old motor in my workshop, stripped out the rather large chunky carbon brushes cut 4 x pieces down with the angle grinder and slotted these in front of the worn out ones, so giving them an extra 10mm of 'new' carbon brush material.
all back together and bench tested with a battery, works great on all 3 speeds :thumbs: happy days