Condenser fan test without any AC refrigerant
 

Hi all, back once more with some quick questions about my ZT.

Now that the sun is out again, I have found that the AC is not working in my car. Looked around the forum for a bit, and I found the standard condenser fan check. With the engine on, AC off, and the demist function on my fan is not spinning at all. I have a 2002 ZT and I don't see a silver/gold resistor behind the fan, leading me to believe I have a three speed fan (is this valid reasoning?).

I can see that my condenser is shot, figure it has not been replaced in its 280000 km lifetime. Also, the car had sat for a good 1.5 years before I got it running again, meaning that all refrigerant is probably gone. Therefore, to me it seems like the perfect time to replace the condenser, get some fresh O-rings (from DMGRS) and get her filled up.

Now, the lack of condenser fan movement got me worried that either the condenser fan is broken or the is an electrical issue somewhere in the circuit. This leaves me with three questions:

1: Is my initial condenser fan check valid even if there is no refrigerant in the system?

2: Can I follow the same instructions given here (https://the75andztclub.co.uk/forum/s...=318222&page=2) by Arctic if I have a 3-speed fan? (will the control box be the same, do I measure voltage over the same wires?)

3: If a replacement fan is needed, is this the item I need to get for a ZT 190? (https://rimmerbros.com/Item--i-PGJ000100ASSY)

Thanks in advance!

Fan assembly
 

I think this is the same one but cheaper!
https://www.ebay.co.uk/itm/284482083...EAAOSwDjFbdxO-
Bob

Yes Nathan, on a KV6 that is a reasonable conclusion.
That's a very good question and I'm uncertain of the answer! As you are fitting a new condenser you can check it another way.
No, your control box will be different. It will have three relays rather than two and different wiring colours. Locate your large relay which will be on the right hand side and identify the thin blue wire. Connect a jump lead between that and the black wires on the small relay at the far left hand side. Now turn on the ignition. Does the fan run at slow speed?
That's a two speed replacement with a silver resistor. It's best to replace the silver resistor with a higher wattage gold one. But you don't need to go the considerable expense of renewing the entire fan system. If you do have a three speed motor you can fit new brushes to it and restore operation (provided that the commutator hasn't been damaged).

The best way forward Nathan is not to jump the gun. Take off your front bumper and the fan control box lid will be labelled "KV6" if it's a 3 speed system. With the lid off, photograph the inside if you can and post it here.

I hope this helps.

Simon

Thank you for the elaborate answer. My first course of action was indeed going to be taking the bumper off to try the wire trick if it was also possible with the 3-speed fan. For this it is very good to know which wires to connect, thank you for that! Probably will get around to it on friday, but now I have a plan of how to tackle this.

the trinary switch has an inhibitor pressure switch built in that will not allow the fan the to operate with low or zero pressure present. i think the 3 speed system has an extra wire connection on the loom to box. usually on the 3 speed system the slow speed fan gives up first, so i dont know if your cooling fan is working on all speeds during normal cooling, which i presume you would need to check anyway.

Hi Nathan.
The fans linked to above are for a 1.8 you have a V6 which will have a four wire three speed fan, or it should have unless it as been changed at some time.

V6 control box
https://i.imgur.com/I2Aeecfl.jpg1

https://i.imgur.com/23qyB9zl.jpg2

If you have carried out the demist test then you know that the low speed at least is not working, sometimes it will take the medium speed with it, depending on how bad the brushes have been worn, remove fan from the car and take the motor plate of and check the brushes.

https://i.imgur.com/1WquS8Bl.jpg3

https://i.imgur.com/ls3v2Lal.jpg4

I had a problem with my fan recently and got a lot of help from the forum to fix it up. If you do end up replacing the brushes, it's not too hard to fix them as long as you can do very basic soldering.

Trinary switch
 

Hi Stefan,

Just to clarify, the low pressure switch stops the compressor clutch engaging (via the ECM). Whether this condition also inhibits fan operation is uncertain on a 3 speed system without gas and a suspected fan fault as it's impossible to determine without entering the control box as I've described.

However we could find out if a KV6 owner (Siemens ECM) with operational air con. and a fully functional 2 speed resistor system removes the connector from the trinary switch, starts the engine from cold and presses the windscreen demist button. :}

Simon

Amazing! Will check the brushes once I get to the condenser fan. One quick question: reading on the forum I hear that the metal tabs holding the motor plate are difficult to remove without breaking/disturbing the front bearings. Do you carefully bent them with pliers or something?

Hi Nathan.
I don't know where you read that about the tabs, i have never broken any, or was it you read that the magnets can get broken easy.

link how to take the plate off.

https://youtu.be/ls1BJGxUoPo