Quick fan question

[johnny t]

Iam a bit confused about the fans used of our car's, after reading many threads on the subject I am non the wiser.
My facelift cdti has no resistor, surely it should?
My mk1 260 does have a resistor when I would have thought it shouldn't.
Why is the diesel fan different to the petrol, I understand the control side is different but is that it, do some diesel cars have the resistor?

[Jules]

There was a 2 year overlap when both types of fan were used so it's not body shape related

Control boxes in the diesels have a PWM PCB inside the control box whereas all the petrol variants didn't.
Also the pin configuration on the negative fan plug is different.

[SD1too]

Originally Posted by johnny t

My facelift cdti has no resistor, surely it should?

No; some quite late cars have cropped up with fan systems without the resistor. There's no 'hard & fast' rule.

Why is the diesel fan different to the petrol, I understand the control side is different but is that it ..

Yes; the control box and the PWM signal sent from the ECM is what makes the diesel fan system different.

... do some diesel cars have the resistor?

Yes.

Hope this helps. If you have any more questions; fire away!

Simon

[johnny t]

So if I where to uprate my diesel fan what I am I looking for? And also why does my diesel fan run much faster in aircon mode than my petrol?
Thanks

[wuzerk]

Originally Posted by johnny t

So if I where to uprate my diesel fan what I am I looking for? And also why does my diesel fan run much faster in aircon mode than my petrol?
Thanks

You should fit the 2 speed type to your diesel when it fails on slow speed if possible since they are much more reliable and you should fit the uprated (gold) resistor at the same time (Jules). The one supplied with the fan is not man enough and liable to fail. The 2 speed with its control box is a plug and play replacement. Make very sure that the fan cables are securely tied in so that they cannot rub on the matrix behind them.

[SD1too]

Originally Posted by johnny t

And also why does my diesel fan run much faster in aircon mode than my petrol?

Johnny,

Let's concentrate on your diesel car. Turn on the ignition and press the windscreen 'demist' button on your air conditioning panel. Now walk to the front of the car and listen at the radiator grille. Is the fan running?

If it isn't, your slow speed has failed. The next step will be removing the front bumper (not as difficult as it sounds) to check that you don't have one of the small number of cars with the resistor mounted out of sight behind the fan shrouding.

If you do find that you have a resistor system, buy the 'gold' uprated replacement from Jules.
If you don't have the resistor, and have 4 wires leading from the motor casing, then you have a 3 speed system. Unless you're experienced in car electrics and motor repairs, the best solution is to replace it either with a second-hand 2 speed resistor system from Arctic or a new aftermarket Kenlowe kit from Jules.

First thing is the test, followed by bumper off!

Simon

[johnny t]

Originally Posted by SD1too

Johnny,

Let's concentrate on your diesel car. Turn on the ignition and press the windscreen 'demist' button on your air conditioning panel. Now walk to the front of the car and listen at the radiator grille. Is the fan running?

If it isn't, your slow speed has failed. The next step will be removing the front bumper (not as difficult as it sounds) to check that you don't have one of the small number of cars with the resistor mounted out of sight behind the fan shrouding.

If you do find that you have a resistor system, buy the 'gold' uprated replacement from Jules.
If you don't have the resistor, and have 4 wires leading from the motor casing, then you have a 3 speed system. Unless you're experienced in car electrics and motor repairs, the best solution is to replace it either with a second-hand 2 speed resistor system from Arctic or a new aftermarket Kenlowe kit from Jules.

First thing is the test, followed by bumper off!

Simon

I don't have to go to the front I can hear it inside the car(even with the engine running) , if I do the same on the 260 you have to look, much quieter and slower, is this normal? They are both working as they should I think, just why are they different.
Any ideas

[SD1too]

Originally Posted by johnny t

They are both working as they should I think, just why are they different.

I don't know anything about the 260 fan system I'm afraid, but it's perfectly possible that the motors on each car run at different speeds depending upon the cooling requirements of the engine. We do know that petrols run hotter than diesels.

Simon

[johnny t]

Possible but surely the diesel would run slower
The only time I've ever known it come on is with the aircon, and it's always been the same since new

[SD1too]

Originally Posted by johnny t

The only time I've ever known it come on is with the aircon, and it's always been the same since new

That's normal for the diesel.

Simon