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VZ Cooling Fan and A/C problems HELP!!

Gaz1111

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Hi all, Hoping someone can help me. I've been searching through the forum and have come across a few posts that are similar but not really what I am after.
My car has been overheating and I've noticed that it has been dropping a bit of coolant after a short drive. Have replaced radiator cap and bleed system etc as per many posts. But I've noticed that the drivers side fan doesn't come on at all. The only time it did was when the engine was extremely hot and both fans operated then.
I've attempted to trace through wiring etc and the other weekend I removed the cover from the main relay (5 pin). When I manually operated the relay by pushing the contact both fans would operate. However it doesn't seem to work at all otherwise. The many posts ive read mention that having the a/c on will trigger both fans to run. My Air Con compressor doesn't engage (as I think the solenoid may be open circuit) but I had a thought this morning that perhaps there is something holding both the fans and my A/C compressor out. I was trying to trace the wiring diagram through to see if I could locate it but no.
Does anyone know where the diode for the A/C compressor is located? Or Does the A/C solenoid pick up the negative side of the coil from the frame? I disconnected what I thought was the A/C plug and had 14V across the 2 pins feeding the 'comp' .
It just seems weird that both the A/C and also my cooling fans won't run and they seem as though somewhere they are interlinked?
Any help greatly appreciated
 

99notout

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Have a read of this, it might help.
 

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Gaz1111

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Hi,
Thanks for that.
Makes sense.
I actually got the main cooling fan to operate. It came on at 108 deg C which i think is about right.
The coolant is still overflowing though and I'm not sure why. Everytime I check the level on the engine it is down. I fill up and bleed the radiator but then there always seems to be coolant overflow on the floor afterwards. It doesn't seem like it's getting sucked back up when needed and just overflows the reservoir.
I'm a bit confused. Checked the overflow hose and all!
 

rambunctious

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I did a play around with the fans some time ago and found the very same as you have.
The smaller of the 2 works with air con but the larger only comes on it the car gets hotter.

I have had a few vz's and the drivers fan never works until, as you say, the engine is really hot.
 

krusing

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Air Lock in the cooling system due to a Faulty Thermostat ?
 

99notout

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I'ts probably just a faulty cap. Get an original, not a Tridon.
 

DeanoV6

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Disconnecting the piug on the temperature sensor will start both fans
 

Gaz1111

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Air Lock in the cooling system due to a Faulty Thermostat ?
Thanks,
I don't know... It doesn't seem to have an air lock but it's like it get's hot through normal operation then the excess goes into the cooling tank but doesn't get sucked back in. No holes in hose, etc
I just wonder whether or not the new radiator cap is opening to early?
 

99notout

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If it doesn't siphon back in from the overflow, then it can only really be four things.
1. The cap is faulty.
2. There is a leak allowing air to be siphoned back in (it's easier than coolant).
3. The overflow tube is faulty.
4. The thermostat is faulty, and that won't really prevent contracting cooland syphoning back in from the overflow.

I would rule out the first three.
 
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Gaz1111

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I'ts probably just a faulty cap. Get an original, not a Tridon.
Yes I wondered if that could be a problem... The old one just fell apart and unfortunately it was when my daughter was driving and out of town. This was when the overheating problems began...
 
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