How to replace bushes on 3 speed fan

[SD1too]

Originally Posted by vitesse

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.

What's happening there Mike is as follows.

On a 3 speed system the increases are additive. So medium speed is obtained by activating both the low speed and the medium speed relay. So on a 2 speed system when Toaf earths the UY wire, which is open circuit, the low speed continues to run. That's why you thought you heard low and medium speeds to be the same. In fact you were hearing low speed twice.

Your test also shows that high speed is triggered at 112 degrees and not 105/106 degrees. Something very strange is going on with Joe's car. I would like to see which colour wires are connected to which pins in the loom plugs. Unfortunately that's impossible at the moment with the photos posted.

Simon

[vitesse]

Originally Posted by SD1too

What's happening there Mike is as follows.

On a 3 speed system the increases are additive. So medium speed is obtained by activating both the low speed and the medium speed relay. So on a 2 speed system when Toaf earths the UY wire, which is open circuit, the low speed continues to run. That's why you thought you heard low and medium speeds to be the same. In fact you were hearing low speed twice.

Your test also shows that high speed is triggered at 112 degrees and not 105/106 degrees. Something very strange is going on with Joe's car. I would like to see which colour wires are connected to which pins in the loom plugs. Unfortunately that's impossible at the moment with the photos posted.

Simon

Thanks Simon, I'm going to open the 2 speed control box and have a look but could you tell me which colour(s) triggers which speed just so I can get my head around this?

Mike

[SD1too]

Originally Posted by vitesse

... could you tell me which colour(s) triggers which speed just so I can get my head around this?

Of course Mike.
Yellow is the +12v supply to both relay coils (always live).
Blue is earthed by the ECM to operate the low speed relay (small, centre position).
Blue/red is earthed by the ECM to operate the high speed relay (large, end position).

Simon

[vitesse]

Originally Posted by SD1too

Of course Mike.
Yellow is the +12v supply to both relay coils (always live).
Blue is earthed by the ECM to operate the low speed relay (small, centre position).
Blue/red is earthed by the ECM to operate the high speed relay (large, end position).

Simon

Thanks Simon, got a 2 speed in front of me but non-resistor K18 can't find any SRB2, but 772-65030-03. But on this one, blue goes to the larger relay, blue/red to the smaller but central relay. Of course, blue/yellow is absent on this loom, but on a 3 speed fan that would then operate medium speed, correct?

Mike

[SD1too]

Originally Posted by vitesse

... got a 2 speed in front of me but non-resistor K18 ...

That should be a lower power motor for the 1.8 litre engines and is the early design with the large and small relay function opposite to the resistor type. The U and UR wires are still slow and fast speeds respectively.

Originally Posted by vitesse

Of course, blue/yellow is absent on this loom, but on a 3 speed fan that would then operate medium speed, correct?

Yes.

Simon

[phenonix]

Originally Posted by vitesse

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.

When i say noisier i mean more powerful.

[phenonix]

Originally Posted by T-Cut

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

Just to clarify on this, the temperature dropped from 102/3C to 97C with no fan moving.
i had the front of the car of and observed this numerous times.

I keep using the term loud/noisey, what i really mean is it is very powerful.

[phenonix]

Originally Posted by SD1too

What's happening there Mike is as follows.

On a 3 speed system the increases are additive. So medium speed is obtained by activating both the low speed and the medium speed relay. So on a 2 speed system when Toaf earths the UY wire, which is open circuit, the low speed continues to run. That's why you thought you heard low and medium speeds to be the same. In fact you were hearing low speed twice.

Your test also shows that high speed is triggered at 112 degrees and not 105/106 degrees. Something very strange is going on with Joe's car. I would like to see which colour wires are connected to which pins in the loom plugs. Unfortunately that's impossible at the moment with the photos posted.

Simon

I have this photo of the wires into the relay

[vitesse]

Originally Posted by phenonix

When i say noisier i mean more powerful.

Mine is the opposite, quieter on demist, noisier (more powerful) on 2nd speed.

In my post no.84, my blue trigger wires are reversed, does your motor have a resistor?

Regards

ps Get Toaf you'll be amazed what it can do ... testing fans is just a small part

[phenonix]

Originally Posted by vitesse

Mine is the opposite, quieter on demist, noisier (more powerful) on 2nd speed.

In my post no.84, my blue trigger wires are reversed, does your motor have a resistor?

Regards

ps Get Toaf you'll be amazed what it can do ... testing fans is just a small part

I'm looking into Toaf right now.

I've installed the gold resistor.

Big wires reversed? Not sure.
Big learning curve for me on this, fan operations.
Heres me thinking everything is fixed and now it's thought my is weird, not looking forward to taking the from apart again!