Aux a/c Fan Wiring

[1996LandCruiser]

I installed an electric fan a a couple of months ago for the purpose of boosting a/c performance in city driving. The wiring is complete except the run signal to the relay. I have been trying to figure out where to wire this to. The fan should run whenever the a/c is on so wiring it to the hi pressure switch won't work. An on/off switch would be pretty easy to do but it would be nice if I didn't have to turn the fan on manually.
Any thoughts?

Thanks, jt

 

[Ming89FJ62]

you could always tap the lead to the clutch. Clutch on - fan on.

 

[1996LandCruiser]

Thanks for you reply! Yes that is true; however I seem to recall a recommendation against doing that. Can anyone confirm this? Thx.

 

[DARKNESS]

ABC's of 80's Cooling Part II - Aux Fan Wiring

 

[DARKNESS]

ABC's of 80's Cooling Part III - Press Switch

 

[LandCruiserPhil]

I just kept it simple...fan draw is only 5A so no relay needed. Unswitched Power - switch - fan

 

[1996LandCruiser]

Thanks for posting those 2 threads Darkness. Those pretty much cover all the options. Nice switch install Phil. That location would work well for me as my relays, fog lights and fan, are mounted on the DS firewall. I will probably try out the compressor lead into relay pin #85 and see how that works. I can get it done quickly although I have a suitable switch laying around also. I appreciate all the replies!

 

[SUMMIT CRUISERS]

Thanks for you reply! Yes that is true; however I seem to recall a recommendation against doing that. Can anyone confirm this? Thx.

I had an aux fan hooked up this way in the past. Battery was weak, wife left the switch on and upon starting it the clutch could not engage properly with enough voltage. Clutch melted into a black goo. Replaced clutch, wired aux fan to its own power source and relay. All has been good. The aux fan is only needed at slow speeds or stopped and idling to boost AC performance/engine cooling.