Factory Thermo Fan

[benro2]

Was just wondering, is it possible to have the factory thermo fan come on when the A/C compressor kicks in? I've never seen it turn on before as I understand it's only for emergencies - but is it very loud? I wouldn't bother attempting this if it's going to make a racket...

The reason why I ask is only because when the car has been sitting in the heat for a while and you're trapped in traffic or a carpark or whatever, the A/C doesn't cool down as much as when I start driving. I only have to be doing about 40km/h and it cools right down, so I'm thinking that this second fan would greatly help in bringing down the interior temps while stopped.

Also BTW, does anyone know if the climate control automatically puts the recirculating air on when the car is boiling hot? I've never seen that light turn on by itself so I don't know if it actually ever does recirc the air, but in every other car I've been in that has climate control, it recircs the air straight away if it's boiling hot outside! Kinda seems a bit stupid considering it could be like 60-70C+ inside the car when it's "only" 40C outside... so wouldn't it be smarter to have it recirc only after the interior temp has reached below what it is outside? Then once the car is close to the set temp, turn the fresh air back on?

Edit: forgot to ask, why exactly did Nissan go for a clutch fan? Is it because it's more powerful than an electric fan? Surely there are electric fans around that can match the CFM of the clutch fan? Could it be something to do with cost or weight?

Edited January 1, 2010 by benro2

[heller44]

Yes it is possible..

here is a diy for '32.. I don't know about the wiring on a '33 but theory should be the same. http://www.skylinesaustralia.com/forums/R3...html&hl=fan

[blind_elk]

When you start a hot car on a hot day, the A/C / climate control should be set to "fresh" and a window opened so that it pushes the hot air out and replaces it with the cooled A/C air. When the inside of the car is at a more reasonable temp, window up, A/C to "recirc".

If you intercept the thermo switch wiring (switch in the bottom tank of the radiator), rewire it through a relay to the A/C clutch. Then it will switch on when the A/C clutch engages.

[heller44]

Why add another relay in there, just shunt the signal over to the relay already fitted.. one diode..

[benro2]

When you start a hot car on a hot day, the A/C / climate control should be set to "fresh" and a window opened so that it pushes the hot air out and replaces it with the cooled A/C air. When the inside of the car is at a more reasonable temp, window up, A/C to "recirc".

But that's the thing, it *appears* that it's set to "fresh" (ie: recirc light is off), but just from the feel of the temp of the incoming air, plus from experiences with other cars, they always go into recirc mode when it's really hot. I know I could just push the recirc button twice to force it onto fresh air, but just interested in *why* they do this, when it's logical that fresh air would be the go while it's hotter inside the car than out!