Cooling fan relays
Cooling fan relays I am installing the cooling fans into my 56 chevy/LS1 project. I am using dual cooling fans from a 2002 corvette.
My wiring diagram shows that I am supposed to have 3 relays. Is that correct?
Any way to get it done with 1 or 2 or do I need all 3?
Thanks,
My wiring diagram shows that I am supposed to have 3 relays. Is that correct?
Any way to get it done with 1 or 2 or do I need all 3?
Thanks,
If you use 3 relays like the stock harness did, then you get a low speed and a full speed for the fans. Both fans at low speed is a LOT quieter than 1 fan at full speed, and cools better too. I originally wired mine with 2 relays (Low = 1st fan, High = 2nd fan), but once I realized what the 3rd relay did (switched the fans between "series" and "parallel"), I went back and rewired for 3 relays.
If you use 3 relays like the stock harness did, then you get a low speed and a full speed for the fans. Both fans at low speed is a LOT quieter than 1 fan at full speed, and cools better too. I originally wired mine with 2 relays (Low = 1st fan, High = 2nd fan), but once I realized what the 3rd relay did (switched the fans between "series" and "parallel"), I went back and rewired for 3 relays.
Does this only work for cooling fans that work that way? Like stock GM fans etc.... Or will adding the 3rd relay turn any dual fan setup into low/high setup. I have a duel flex-lite setup and was wondering if that would work.
It'll work with any normal pair of fans with 3 relays. For that matter, you could use two old fashioned temp switches instead of the LS1 PCM to control the relays, although if you've got the computer, might as well use it!
I went out and wired it up, used regular 4 pin relays for the fans and a 5 pin for the other relay, its what I had and looked like I didn't need the 5 pin for the main relays.
Fired her up and the fans, both kicked on at 172 degrees, according to my digital dash sending from the p-side head (rear). Engine wouldn't get over 180 degrees but seems like both fans were runnign slower. Going to grab a amp meter and see what current draw is wired up like this and straight wired.
Thanks guys!
Fired her up and the fans, both kicked on at 172 degrees, according to my digital dash sending from the p-side head (rear). Engine wouldn't get over 180 degrees but seems like both fans were runnign slower. Going to grab a amp meter and see what current draw is wired up like this and straight wired.
Thanks guys!
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How does it cool better if the Fans are spinning slower if it's pulling less air through..
When I did my swap into my Camaro, I re-wired the whole Fuse Box, and wired my Fans to a Manual Setup, 2 switches, 2 Relays, High speed only.
When I did my swap into my Camaro, I re-wired the whole Fuse Box, and wired my Fans to a Manual Setup, 2 switches, 2 Relays, High speed only.
Two fans spinning at half speed will cool better then one fan at high speed, since its pulling air over more radiator surface. When it is required both fans go to high speed.
True.. I'll have to look into getting mine to both spin at low, then at high.
Is it hard to wire it for that, I know how to wire a Relay, you just make one circuit Parallel, then the other Series?
Is it hard to wire it for that, I know how to wire a Relay, you just make one circuit Parallel, then the other Series?
If you can't find the diagram, email me, I'll send it to you. I have it on paper, but could just save it as a PDF file and send it to you. I bought CP S10 swap radiator and am going to wire the twin fans on it that way
Just in case Here are the schematics for the fan wiring from a 2004 Express van. It will work the same for the F-Bodys, just have to change the PCM pins to the corresponding pins on your PCM.
Two fans on low draw a lot less amperage then the two at full speed. I idled the car the other day, 80 degrees out and the fans ran nice and quiet, engine sat at 176 degrees.
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Joined: May 2004
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From: SoCal
At what temperature does the PCM switch on the low speed and then the high speed fan circuits?
If the PCM temp switching is too high, can you use two different temp switches on the motor or radiator to switch for the low and high circuits? Is there a prefered temp switch that I should look for? I noticed some turn on at say 200 degrees, then turn off at a lower temp.
Thanks a bunch,
Andy1
If the PCM temp switching is too high, can you use two different temp switches on the motor or radiator to switch for the low and high circuits? Is there a prefered temp switch that I should look for? I noticed some turn on at say 200 degrees, then turn off at a lower temp.
Thanks a bunch,
Andy1