Well so you know i just did a search for this informaion and didnt get what i was looking for.

So here's what my dilemma is:

First off i'll admit i hate doing electrical, but will cuz i'm to cheap to pay someone for something i know i can do myself...lol.

I just picked up a dual fan setup out of a lt1 camaro for a mere $10 at my local wrecking yard.

I would like to find a kit that i can use to wire in these fans.

My rig also has AC on it.
Its a 2003 blazer with a 4.3 if that matters.

i'm not sure how the "dual" fans work on a regular car. If they both run at the same time, or if one is for the engine temp and the other for the ac??

Here is one of the kits i'm looking at, but not sure?

(and i'm hard pressed to spend $150 from summit for a dual fan wiring kit!)

Thank you very much for all your responses ahead of time!


Painless Performance Dual Activation Fan Relay Kit

 

You can do this with three relays and a temperature switch or two. Basically, you can wire it up to run the fans in series (+12V to one fan, the ground lead from that fan to the + lead on the 2nd fan, then grounding the ground lead on the 2nd fan) whenever the temperature switch closes (reaches its set temperature). This will run both fans at half speed. Then you wire the A/C compressor clutch into the circuit to trigger the fans to run in parallel (both supplied with +12V & ground). I don't have anything to draw up this circuit... Let me see what I can dig up.

*EDIT* - Found this over on the12volt.com searching for dual electric fan (see the attached). If you can find a dual temp switch (I seem to remember either a BMW or Mercedes switch that had two set temperatures), you could add that to the high speed trigger. I recommend tying the A/C clutch in for high speed as well. This will improve your A/C effectiveness on hot days. Use a diode on each of the high speed inputs to isolate them.

*EDIT2* - I hate to do it, but I gotta link to a Ford site... Good list of temperature switches.

Well, I feel better now. Here's a link to ColoradoK5.com for a discussion on installing Ford (damn it - did it again) Winstar fans. The final wiring schematic is pretty involved, but great for offroad use! POST where Lunatic mentions the dual circuit temp switch. POST with final wiring schematic (also attached). Awesome fab work in that thread as well!! Only thing here is that that I don't think this setup runs the fans in series, only each fan separately or both together.

 

I just installed my LS1 setup yesterday. I used the Flex-a-lite VSC (Variable Speed Control). Seems to work great. Only had to tap into ignition supply (just as a signal) and ac. Very easy to install. I had my whole system installed and running in just shy of 2 hours.