Black_Magic

Here is a possible solution for wiring AUX cooling fans. May also be helpful for electric fan setups.

A little background first:

With all the post about heating problems I got paranoid after adding A/C and driving in St. Louis 95+ summer heat. I look at many many post as to problems and solutions. I think in the long run I went overboard BUT in the final analysis I have been driving lately with A/C on and the engine temp stays around 180-185 reguardless of highway or slow traffic or stop & Go

Temp taken after stop & go driving. Taken at sending unit.


I made changes in steps to evaluate each as I went along and here is how I rate them as to effect.

(1) Dewit Radiator (942b) and new lower hose
(2) Lower shroud seal
(3) 18 inch 6 Blade clutch fan (Flex-a-lite 5918)
(4) Sealing sides of radiator to shroud
(5) 1966-67 Upper Air Dam
(6) Aux Fan wiring (what this post is about)

Now to the purpose of this thread Before adding fan/seals I would see temps, after exiting highway and/or slow stop & go traffic, climb quickly above 200 and after stoping 220+. With A/C off the AUX fans were not running and probably restricting air flow. So I came up with a solution to use them when temp got high.

Now that I have competed items 1-5 above I probably don't need item 6. But the fans have kick on after a long highway drive and parking soon after.

NOTE: Wired the way I did the fans will kick on even with key off. So I would be very carefull if you don't have NEW wiring (I do) and make sure this is an isolated circuit that is fused. OR wire into a key circuit. Check wiring diagram and wire accordingly.


Click here for ===>>> Aux Fan wiring

Another note After adding Dynamat, underbody insulation and tinting windows I have enjoy a cool cockpit as the A/C output temp at vent is 37 degrees.

Best

George

6T5RUSH

Black_Magic,

Thank you for the descriptive and informative approach. The pics were worth a 1,000 words!! I have done all those things you mentioned to manage/enhance the cooling system. I too have added the CAA system to my small blcok. I've done the sealing the shroud, DeWitt's rad, factory A/C seal on top, mapped the ignition system (did improve the cooling). I too feel why not take advantage of the 2 Spal fans that only turn on when the A/C compressor is running (for those traffic jam situations we all end up in).

Thanks for your approach. Will be adopting all if not most of your methods. Just makes sense to have her automatically kick on at a pre-set temp (which you select). Do like the additional feature of being able to manually kick in whenever I want as well.

Regards,

Jim

ragedout

i like the idea of the fan coming on auto and off at certin temps. just because you turn off the car dosent mean its cooled down. or you could have one fan come on at one temp and the other fan come on when the temp goes 50 or so degrees higher to help it stay cooler sooner.....mike