CDT cooling fan same as v6

[badrover]

My 2002 tourer has the usual cooling fan issues - there is no slow speed working but The high speed runs continuously with the A/C on.
I have a spare 2.0 V6 known working radiator and fan assembly from a 2001 car. If I just swap the resistors, will this work or am I looking at this to simplistically?

[Arctic]

The petrol fan will not fit wiring is different and it as no PCB board in the control box, if it is a two wire 2 speed with resistor it can be adapted but this involves using you diesel control box.

First do the demist test do you know which fan you have fitted four wire 3 speed no resistor or the two wire 2 speed with resistor ?

[RayH]

Originally Posted by badrover

My 2002 tourer has the usual cooling fan issues - there is no slow speed working but The high speed runs continuously with the A/C on.
I have a spare 2.0 V6 known working radiator and fan assembly from a 2001 car. If I just swap the resistors, will this work or am I looking at this to simplistically?

When you say swap the resistors, do you mean that the failed unit also has a resistor on it?

[Arctic]

Hi Ray.
Yes did cross my mind if David as a silver resistor in place and if so all the OP would need to do is replace it with a gold resistor from Jules

[badrover]

Sorry gentlemen, I wasn't very clear! On my car, a 2002 CDT:
The demist button makes the fan kick in at a very high speed. It sounds like a jet taking off! In the winter months it tends to kick in and out at high speed, every ten seconds or so. Now it's summer, the high speed is on all the time the demist is activated.
I've never seen or heard the fan kick in at a lower speed.
Looking through the grille I can't see a resistor.

My spare radiator, fan, cowl and control box assembly:
Came from a 50k mile 2001 2.0 V6
I know it works on low speed with demist depressed.
I know it cycles on and off to cool the engine as necessary.
Also doesn't have a visible resistor.

My basic question is whether I can butcher the spare V6 radiator assembly for parts to make my CDT one work? Or, do I need to spend some money on it? I only ask ask as I paid £300 for the CDT as a hack. It's been super reliable over 22k miles but there is rot in the sill, I think the brake servo us past it's best, the back box is shot and it's nearly on 200k miles. I don't want to throw money at it unnecessarily as the next mot might be financially prohibitive!
Sorry if I wasn't too clear and tanks for your thoughts so far.

[RayH]

Originally Posted by badrover

Sorry gentlemen, I wasn't very clear! On my car, a 2002 CDT:
The demist button makes the fan kick in at a very high speed. It sounds like a jet taking off! In the winter months it tends to kick in and out at high speed, every ten seconds or so. Now it's summer, the high speed is on all the time the demist is activated.
I've never seen or heard the fan kick in at a lower speed.
Looking through the grille I can't see a resistor.

My spare radiator, fan, cowl and control box assembly:
Came from a 50k mile 2001 2.0 V6
I know it works on low speed with demist depressed.
I know it cycles on and off to cool the engine as necessary.
Also doesn't have a visible resistor.

My basic question is whether I can butcher the spare V6 radiator assembly for parts to make my CDT one work? Or, do I need to spend some money on it? I only ask ask as I paid £300 for the CDT as a hack. It's been super reliable over 22k miles but there is rot in the sill, I think the brake servo us past it's best, the back box is shot and it's nearly on 200k miles. I don't want to throw money at it unnecessarily as the next mot might be financially prohibitive!
Sorry if I wasn't too clear and tanks for your thoughts so far.

Okay, let's just check one thing first.
Turn the ignition on, do NOT start the engine, press demist and what does the fan do? Nothing, slow or fast and is it continuous?

But to answer your question broadly then yes, you should be able to do something with the other one, although the working one sounds like a three speed too so has the potential to go wrong any time soon unless you want to do a little preventative maintenance on it.

However, do the check first and let's see what is happening.

[badrover]

Thanks, I've done the test and the fan did nothing at all.

[RayH]

Originally Posted by badrover

Thanks, I've done the test and the fan did nothing at all.

So the low speed has failed, and this is most likely to be brushes.
Because the AC condenser is not being cooled the pressure in the system increases to the point where the trinary switch operates the higher speed for a period.

The three speed fans are a bit notorious, plenty of threads on here, for getting though these.

You can do a straight swap of the motors if they are both 4 wire, as you suggest they are, but retain the original control box mounted adjacent to the fan, as the petrol and diesel variants are different.

Depending on the "mileage" on the good fan you may want to consider fitting new brushes, or at least checking them, before fitting it to the car.

Brushes can be obtained here http://www.engineeringcarbonproducts...on-brushes.php
Note they incorrectly describe them as Heater Fan Brushes. The brushes are right, the description is wrong.

Hope this helps.

[badrover]

That's great, thanks for the comprehensive response. Will check brushes before fitting and report back.