Cooling Fan Internals

[SD1too]

Originally Posted by Billy1mate

... the aircon doesn't flash up full stop.

Ade, what do you mean by "flash up"?

It should run up without the fan ...

Absolutely right. A malfunctioning fan does not directly stop the air con. compressor, but let's stick to the fan problem for now otherwise things will get very complicated.

... then switch off if the fan doesn't run up.

Err ... no. The air con. will not switch off if the fan doesn't run up. You've been misled there.

Ade, from where did you get the spare PCB and relays? I think we need to start doing some electrical tests. Do you have a multimeter?

Simon.

[Billy1mate]

When I say 'flash up', i mean the aircon will operate as normal. As for the relays & pcb, they came from a scrappy & they 'guaranteed' that they'd work. I am wondering if there is a problem somewhere else. I do have a multimeter but I'm an oily hands type, I can check bit 'n' pieces but I'm not brilliant at it.
As an aside I took the ECU out to check for water ingress I think it has has some water in it in the past but it was bone dry, the circuit board has a water mark only around the very edge & there doesn't appear to be any water marks on the components on it, there could be a dry joint but it all looks ok.
Could both pcb's be duff?

[Arctic]

Originally Posted by Billy1mate

When I say 'flash up', i mean the aircon will operate as normal. As for the relays & pcb, they came from a scrappy & they 'guaranteed' that they'd work. I am wondering if there is a problem somewhere else. I do have a multimeter but I'm an oily hands type, I can check bit 'n' pieces but I'm not brilliant at it.
As an aside I took the ECU out to check for water ingress I think it has has some water in it in the past but it was bone dry, the circuit board has a water mark only around the very edge & there doesn't appear to be any water marks on the components on it, there could be a dry joint but it all looks ok.
Could both pcb's be duff?

Try the PCB from the scrap yard with your original relays, and visa-versa making sure the spade connectors are in the right place and tight, also check the earth behind the light attached to the body to see if it needs cleaning up,

[Billy1mate]

Ok, ive swapped relays, pcb's etc...no change, still no fan. So I decided to check, just to be sure, that the fan motor was working.....So here is the massive egg landing in my face, the fan doesn't work.
I connected hefty mains cable to red & black on the fan with corresponding red & black on the battery & no go, then tried speed 2 still no joy even with spinning the fan by hand to coax it along, nothing. So even though it was re-brushed in an electrical workshop & allegedly 'tested' as working. I should have bit the bullet & bought a complete new set up.

[SD1too]

Originally Posted by Billy1mate

... it was re-brushed in an electrical workshop & allegedly 'tested' as working.

If you paid for this work then you can take the motor back to them and ask them to have another go, or give you your money back.

Simon.

[Billy1mate]

It was done at work and they've probably eaten the chocolate hob nobs. I could kick myself for not checking it earlier. Sort of thought it not necessary though when they overhaul aircraft starter/generators on a regular basis, live & learn I suppose. Thank you for your hints and tips, much appreciated.

[SD1too]

O.K., if you're now sure that the motor is the problem, you have five options:

1. Renew the worn brushes, but properly this time, and away you go!
2. Replace with a used 2 speed, 2 wire motor with resistor and control box from another diesel. Upgrade resistor if necessary.
3. Replace only your motor with a 2 speed, 2 wire type. Add upgraded resistor, modify wiring & control box.
4. Replace with brand new MG Rover two speed motor & control box (for a diesel).
5. Replace with Kenlowe conversion, modifying wiring.

4. is the easiest, but the most expensive. 3. is the most complicated and potentially troublesome. Your choice will depend upon how much DIY you want to do, and how much you want to spend. Jules will give you prices and instructions for the Kenlowe conversion.

Simon.

[Arctic]

Originally Posted by Billy1mate

It was done at work and they've probably eaten the chocolate hob nobs. I could kick myself for not checking it earlier. Sort of thought it not necessary though when they overhaul aircraft starter/generators on a regular basis, live & learn I suppose. Thank you for your hints and tips, much appreciated.

Originally Posted by SD1too

O.K., if you're now sure that the motor is the problem, you have five options:

1. Renew the worn brushes, but properly this time, and away you go!
2. Replace with a used 2 speed, 2 wire motor with resistor and control box from another diesel. Upgrade resistor if necessary.
3. Replace only your motor with a 2 speed, 2 wire type. Add upgraded resistor, modify wiring & control box.
4. Replace with brand new MG Rover two speed motor & control box (for a diesel).
5. Replace with Kenlowe conversion, modifying wiring.

4. is the easiest, but the most expensive. 3. is the most complicated and potentially troublesome. Your choice will depend upon how much DIY you want to do, and how much you want to spend. Jules will give you prices and instructions for the Kenlowe conversion.

Simon.

HI Ade.
I opted for No 3 when my threed speed fan pics in this thread went had to use my threed speed control box and wiring as the noddy whom sent the two speed had cut all wires short in the control box, wiring diagram below also link for new fan with control bargain price i think at present you can also make an offer



http://www.ebay.co.uk/itm/3209663759...989%26_rdc%3D1

I only yesterday replaced the condensor and fan on my MG ZT

[Mike Noc]

Originally Posted by SD1too

O.K., if you're now sure that the motor is the problem, you have five options:

1. Renew the worn brushes, but properly this time, and away you go!
2. Replace with a used 2 speed, 2 wire motor with resistor and control box from another diesel. Upgrade resistor if necessary.
3. Replace only your motor with a 2 speed, 2 wire type. Add upgraded resistor, modify wiring & control box.
4. Replace with brand new MG Rover two speed motor & control box (for a diesel).
5. Replace with Kenlowe conversion, modifying wiring.

4. is the easiest, but the most expensive. 3. is the most complicated and potentially troublesome. Your choice will depend upon how much DIY you want to do, and how much you want to spend. Jules will give you prices and instructions for the Kenlowe conversion.

Simon.

There is a 6th option for the CDT Simon, not for the purists but ideal for those on a tight budget: fit any fan you have laying around. If a 214 single speed fan works fine in our temperate climate (and it does) then I can't really think of one that won't.

Mike

[FrenchMike]

Totally agree with you Mike;even here in south of France,very rarely the fan kicks on !

Mike