How to replace bushes on 3 speed fan

[T-Cut]

Hi Joe. There's another test you might do for us to help clarify how the later 2-speed fan operates compared with the earlier 3-speed in a KV6. Can you compare (subjectively, the sound level) the speed of the fan when you do the Demist Test with the speed it runs at when the engine reaches 100 degrees or so? Logically, they will either be equal or the second will be faster. It will help to clarify a question that's been around for years but apparently never looked at.
Many thanks.


TC

[vitesse]

Originally Posted by T-Cut

Quite so, so it seems current understanding isn't right. However, if the 'low' speed duty is covered by Speed 1 and the old 'medium' and 'high' duties are covered by Speed 2, then I think it all fits. This proposal would also explain why several observers over the years have reported 'no difference' between the medium and high speed T4 tests on a later 2-speed system. Clearly one or the other and simply by replacing the resistor, Joe got things back to normal.


TC

I've found when testing a 2 speed motor with Toaf that low, medium and high are all activated, which quite frankly I don't understand as the control box only has two relays. When testing a 3 speed fan I understand that all three triggers are activated one at a time. Suppose the logical thing would be to check which of the three triggers is absent in the 2 speed loom, but then how can the 2 speed motor be activated at all three levels?

Regards

[phenonix]

Seen “Toaf” a few times now, what is that?

[T-Cut]

Originally Posted by vitesse

I've found when testing a 2 speed motor with Toaf that low, medium and high are all activated, which quite frankly I don't understand as the control box only has two relays.

Hi Mike, thanks for your input. I guess the reason for your observation is that the 2-speed contol box is wired to enable the 'medium' speed test to trip one or other relay. The question here becomes how do the three tests compare with regard to fan running speed? Logically two were the same and one was different. Which two were the same?


TC

[phenonix]

Originally Posted by phenonix

Seen “Toaf” a few times now, what is that?

I’ve looked it up, was not aware that existed.

[phenonix]

Originally Posted by T-Cut

Hi Joe. There's another test you might do for us to help clarify how the later 2-speed fan operates compared with the earlier 3-speed in a KV6. Can you compare (subjectively, the sound level) the speed of the fan when you do the Demist Test with the speed it runs at when the engine reaches 100 degrees or so? Logically, they will either be equal or the second will be faster. It will help to clarify a question that's been around for years but apparently never looked at.
Many thanks.


TC

100....Nice and quiet
Demist... Much higher/ noisier....

[SD1too]

Originally Posted by phenonix

I've tried my Aircon and it seems to be cooling exactly as before (which has never been super cold since i bought the car)
...

Perhaps your refrigerant charge is low. If so, the system would have to work harder raising the high pressure side which might trip the trinary switch to run the high speed radiator fan ....

Originally Posted by phenonix

100....Nice and quiet
Demist... Much higher/ noisier....

I'm not saying that this is definitely the case but now would be a good time to book a specialist to check your air conditioning system and recharge it if necessary.

Simon

[vitesse]

Originally Posted by phenonix

100....Nice and quiet
Demist... Much higher/ noisier....

Sorry but that sounds odd to me. On Monday I fitted a new 2 speed fan to an owner's car. Tried the demist test and it was not noisy, I actually went to the front of the car and then heard it clearly, confirming by using a torch to shine through the grille to see the rotating blades - and no: there's nothing wrong with my hearing.

Regards

ps. Note to Steve: Not even close to my previous 3 hour record, torx problems, welded a flat bar to remove those on the headlamp panel, and had to drill one of the fan motor torx out.

[T-Cut]

Originally Posted by phenonix

100....Nice and quiet
Demist... Much higher/ noisier....

Oh, that's interesting.
There's clearly an underlying aircon issue since when running normally trips the lower speed (Speed 1 as I prefer with 2-speed fans). Your earlier results (before the resistor fix) indicated the same thing. Over-pressure and the under-performance of the aircon's cooling points to poor condensation. That's typically by loss of the fins on the matrix or physical blockage of the airflow.
An extreme case.



However, if we assume that with your aircon operating normally, fan Speed 1 would be tripped on and both tests would give the same result.

The 106C trip point fan speed is the next question. You noted that before the resistor fix, the 106C fan was 'very loud', which 'stopped' at 102/103C - and it then cooled to 97C. Clearly, the loud noise stopped but not the fan itself.

The conclusion I draw from this observation is that Speed 1 covers the 'Low' speed duty of the old system and Speed 2 covers the 'Medium' and 'High' speed duties. This contrasts with Jules' data on the 2-speed diesel system, where Speed 1 operates over the 'Low' and 'Medium' speed duties. If that's so, there's still a complication to explain. Of course a few more examples to provide more results would help with that.

TC

[vitesse]

Just been out to check my 2004 V6 with 2sp (resistor) fan. Using Toaf, low and medium speeds are the same (according to my ears), big difference when I activated high speed.

Checked the fan looms too comparing the 2sp to 3sp. The two speed loom doesn't have the blue/yellow trigger that the 3sp has, though how Toaf manages to activate all 3 speeds is beyond me.

Regards