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Lighter-than-you
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The HD spals can draw just over 40 A each, the relays used in the kit are rated to 30/40A. Dual HD Spals at up to 80A draw combined are highly likely to have problems with a 30/40A relay kit. It is just barely adequate with the dual standard spals.
 

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'07 3SS 2WD
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333 Posts
Discussion Starter · #22 ·
The PCMofNC harnesses also wouldn't experience an issue if wired properly. 8ga battery hookups and 10ga fan leads. I highly doubt it's this size wire... It looks closer to a 10ga/12 setup or 12ga all around.
The basic kit is one 12ga wire. The truck kit is 2 12ga wires.

I didn't know the amp rating of the fans when I bought/installed them. Just went with it being OK from PCMofNC. After it torched the relay I started digging into it.
 

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Lighter-than-you
TrailblazerSS
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If you didn't already buy the truck kit, you can get an autocool 125 for the same price. Going from single 12ga to dual on the same 3-relay kit just makes the 40A relay that much more of a weak link. x2 40A fans should be controlled by x2 40A relay kits.. or much better yet an autocool 125.
The reason the relay kits are still pushed is because of the profit margin.. x3 high-quality relays $5 each, $5 in connectors and $10 worth of wire.. that's $200 profit on one relay kit!!!!
 

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TrailblazerSS
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I have a 402ci stroker that seems way more susceptible to heating up, and use the PCMofNC with the 3 relay and manual switch HD Spals. I run the FSR radiator, 160 thermostat, condenser, intercooler. Agree that the aluminum radiators offer more cooling capacity, but had repeated relay failure.

Figuring out why, found the metal plate and the relay box was radiator temp. I got some Nylon 6/6 washers which resolved the heat soak, and no relay failures (knock on wood). The washers dropped temps 60+ degrees, From 200+ degrees to 140.

Best I can tell the all aluminum radiators (like FSR, Cold case) transfers the coolant temp, as factory plastic mount does not suffer from same heat soak (duh Physics, eh). Attached some snippets.

Agree with others - reach out to Kelly, as you have more options. She has been great to help.

factory radiator top is plastic.
View attachment 103272

FSR has aluminum stand offs
OMG I never would have thought of this, good catch!
I too am running an FSR radiator with 160-degree thermostat and PCMofNC dual Spawl fans, etc etc. (engine has only typical exterior mods)
My issue is that it likes to run 200 degrees even in cold weather. I assume either air in the system or innefficient fan design (for FSR use / remember these fans were engineered for stock TBSS radiators) OR, even more likely, poor air direction around the radiator. My next project was to experiment with custom air ducting and/or fan spacing from the FSR.
YOUR revelation makes me wonder if Ive lost a relay due to the heat transfer and thus lost the first stage cooling. I honestly cannot confirm until after the newyear as I am layed up in a hospital bed at Newport Orthopedic Institute having my 3rd back surgery (total lumbar fusion) . I'll have to check this out as soon as I can get back onmy feet.
 

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'07 3SS 2WD
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Discussion Starter · #25 ·
Heat transfer through the shroud isn't what killed the basic 3 relay kit. This is what it looked like when I moved it from the plastic Camaro fan shroud to the metal one. Still worked, and you can see the pins are not cooked. Sent the pics to PCMofNC, they said to run it if it's still working...

Rectangle Automotive lighting Tints and shades Wood Electric blue



Finger Thumb Electric blue Tints and shades Fashion accessory



Rectangle Tints and shades Electric blue Fashion accessory Metal
 
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07' (1SS) RWD, flowmaster, Rockford Fosgate power, Pc wheels, rear coils,
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You just gonna put the fans on and give it no electrical help you're a Thug!
 

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07 TrailblazerSS Imp
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I designed my own 3 relay harness to go with my design shroud and efans which I upgraded to higher wattage on my FSR radiator and 160 therm. Plus I designed my own stand alone dual trans cooler set up so my trans temp is usually 140* when cold out and maybe up to 185 when its 100* out side. Coolant temp is normally 170* unless its 100* out then nay get to 195 in stop n go traffic with AC on.
 

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TrailblazerSS
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I designed my own 3 relay harness to go with my design shroud and efans which I upgraded to higher wattage on my FSR radiator and 160 therm. Plus I designed my own stand alone dual trans cooler set up so my trans temp is usually 140* when cold out and maybe up to 185 when its 100* out side. Coolant temp is normally 170* unless its 100* out then nay get to 195 in stop n go traffic with AC on.
Where is the website for all of this?!? I’m very interested in a wide variety of all the things you have to offer.
 

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07 TrailblazerSS
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Kelly was aware that the relay cover was warped when I was swapping from the Camaro fans to the HD. (Connector was fine at the time.) Didn't say sht about needing to run the truck kit.
See below.
Rectangle Water Font Parallel Circle


When it failed, I emailed them again. Was basically told "sorry about your luck, buy the truck kit full price.".
We warranty for a year. Sometimes longer that depending on circumstances. The original harness order was from April 2019. I told you also in email it was concerning to me that we knew the fan patch settings had been modified from our intended file. You even asked me to explain how they worked at one point. I have no idea how they were changed, for how long, and what kind of effect that had.
 

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'07 3SS 2WD
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Discussion Starter · #30 · (Edited)
See below.
I never said the 3 relay kit was bad. It's just not for anything bigger that some stock Camaro fans.

On your site, buying the fan kit with the basic 3 relay and HD Spal fans is an option. An option that all should avoid. "Upgrading" to the relay kit that is needed is not an option.

The only adjustments I made to the patch were to bring the fans on earlier.
 

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At the end of the day, you want 10ga min from the battery. Not 12, not dual 12ga. 10ga, minimum. Only that gauge or larger, can support those peaky 30A+ draws reliably. You might get by for a while with LS1 dual fans and similar OE fans, definitely not with fancier aftermarket dual units.
But reliability is the name of the game here. Why is it so hard for an extra few dollars to use 10ga vs 12ga for only a few feet? Not to mention higher rated relays?

If the manufacturer doesn't state it, ask. Though, dealing with 12V systems for decades, one look and you can usually tell...

If I had my ideal relay based system, I'd have 8ga from the battery to a terminal bar. That would be fused for 80A.-100A. A reset-able circuit breaker would be a nice touch here over a fuse
That then feeds 10ga to 40A or 50A relays.
From relay to fans, I'd have 10ga as well.
All grounds would be 8ga from chassis to terminal bar, then 10ga distributed out from there.

Manufacturers can still maintain their ridiculous margins and profits on these relay systems, the above would add only $20 or so bucks to the parts costs as is when bought in bulk and from places like aliexpress and the like.

Or you know, just buy an autocoolguy setup 85/100/125A are reasonable options. Some are dual fan controllers, others single where you bridge both fans together.
 

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Discussion Starter · #32 · (Edited)
Or you know, just buy an autocoolguy setup 85/100/125A are reasonable options. Some are dual fan controllers, others single where you bridge both fans together.
Am I missing something with the ACG website? All the tabs take you back to the top of the page. Not way to buy stuff?

EDIT...Figured it out. The site is just kinda clumsy.
 

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Mitch808, which autocoolguy setup do you have? I see the appeal of a PWM setup, but I’m beyond confused trying to navigate his website.
 

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Discussion Starter · #35 ·
"Clumsy," is just being too nice. :p
Being and old vet, I figured I'd give him a bit of leeway... LOL

Him calling the magazines for his M16 "clips" repeatedly made me cringe a bit though.

Mitch808, which autocoolguy setup do you have? I see the appeal of a PWM setup, but I’m beyond confused trying to navigate his website.
Scroll all the way down, you'll see the individual items. Double click one. It will take you back to the top of the screen. Scroll back down, and the item will be opened. You can navigate items to the left and right of it from there, but it will always take you back to the top of the page. Just keep scrolling down to the bottom...
 

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Mitch808, which autocoolguy setup do you have? I see the appeal of a PWM setup, but I’m beyond confused trying to navigate his website.
There used to be a 85 and 100A model. I dont see it anymore short of the install directions. So that leaves the 125A unit as the only possible choice.

But normally OE style fans you can get the 85/100. Anything aftermarket non-oe style, 100/125 model.

Website isnt great on a mobile device at all. Better on a PC browser.
 

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Discussion Starter · #37 ·
There used to be a 85 and 100A model. I dont see it anymore short of the install directions. So that leaves the 125A unit as the only possible choice.

But normally OE style fans you can get the 85/100. Anything aftermarket non-oe style, 100/125 model.

Website isnt great on a mobile device at all. Better on a PC browser.
The 85 and 100 are still there.

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Lighter-than-you
TrailblazerSS
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The 85A model is plenty stout for all dual e-fan options for tbss except maybe the dual HD spals (which are a total waste for us anyway) Also you'll have to order their temp sensor and temp sensor adapter for the lower radiator hose.. it's the only location for a temp sensor that is recommended by autocoolguy (and for good reason!)
 
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