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I plan to be doing a brushless fan conversion in the future to replace my Mark VIII fan I currently have. If anyone has one they probably know how much of a amperage draw the Taurus/Mark VIII fans have. Especially on start up. From reading up on them the brushless fans are incredibly powerful while being less amperage thirsty. A majority of them also have "soft start" feature built in to them. On top of that they can be setup as a variable speed fan that only goes full blast when needed which would further save on amps.
This allows my factory coolant temp sensor to operate the variable fan speed by programming a "minimum fan speed" turn on temp and then a "maximum fan speed" temp. The AC would be wired to it as well to activate either a selectable 50% or 100% fan speed. Wiring wise this whole setup would actually be simpler than the 2 speed wiring setup I currently have for the Mark VIII fan. Not shown in the diagram, the fan has a large ground and a large power feed. A fused power feed would be activated via relay from the battery utilizing the EBL Flash ECM fan trigger. That way I have control over fan shut down at highway speeds if needed. If my head is thinking right I will have the EBL activate that relay at say 150* (well below what the PWM controller would activate the fan). Then if I program it to shut the fan trigger down at say 65mph it will cut power to the fan.
Following this diagram I threw together. This will likely be completed at the same time I do my AC rehab so I included my AC control wiring with the EBL Flash ECM in the diagram.
Right now I am looking into doing the C7 Corvette fan & shroud. Although I believe there are also some BMW fan setups that would also fit.
I have some amp draw info on my c7 fan installed in my c6.
15% 50% and 89%. it shut off at anything higher than 90 and lower than 12% I believe it was.
the fan is amazing for the price. there's also a zl1 camaro fan that's even higher powered but harder to fit in stuff. this should be more than enough. I have mine wires straight to the alt terminal with a 60amp jcase fuse. they are slow blow and the inline holders aren't to expensive with 8ga wire and then grounded straight to the head. it took a ton of load off my factory wiring and everything is happier
I would recommend STRONGLY against powering that the way you are showing it. You have "12V key on" going toward the motor, meaning, ALL the fan current, is going to be routed through your ign sw, C100 twice, and all the car's wiring. Better to connect that straight to the batt; preferably, through #10 or larger wire with a 14 ga fusible link, and hook it up at the alt output terminal. Use at least a 40A relay to switch it, with its coil connected between "12V key on" and ground.
Also, I seriously doubt the CTS will work right, hooked up to 2 different things. (ECM & fan ctrl) You'll almost certainly need an addl sensor.
Great info thank you! Yes at $270 plus tax/freight for a brand new GM part you can't really beat it. They are manufactured by Spal for GM as well so the quality is there. I would imagine 50% alone is probably pulling air pretty good.
I would recommend STRONGLY against powering that the way you are showing it. You have "12V key on" going toward the motor, meaning, ALL the fan current, is going to be routed through your ign sw, C100 twice, and all the car's wiring. Better to connect that straight to the batt; preferably, through #10 or larger wire with a 14 ga fusible link, and hook it up at the alt output terminal. Use at least a 40A relay to switch it, with its coil connected between "12V key on" and ground.
Also, I seriously doubt the CTS will work right, hooked up to 2 different things. (ECM & fan ctrl) You'll almost certainly need an addl sensor.
The controller is designed to be wired to the CTS that way. Don't know till I try...
The wiring diagram doesn't show the main battery and negative going to the fan motor. The fan has three wires. 12V, Neg, PWM Control Wire. The wire I show is the PWM Control, on the factory harness for the fan it is a significantly smaller wire than the 12V and Neg. I will utilize my existing heavy duty (high amp) relay setup powering my Mark VIII fan. If it can power that fan it will have zero issues powering this brushless fan.
I will utilize my existing heavy duty (high amp) relay setup
In that case, use (don't bother with "utilize") it in front of the PWM ctrl, with its "input" connected as described and its "output" replacing the "12V key on" connection you are showing, as described; and its coil connected between "12V key on" and ground, as described. In NO case would you want the motor current to be drawn off of "12V key on" which will force all that current to pass through C100 twice, the ign sw, and all of that wiring in the car, as described.
The fan motor will not be pulling power through this PWM device. Nor will it be pulling from key on 12V. It will travel straight from the alternator post through a fused 8 awg wire to a heavy duty relay that is triggered via the ecm.
The PWM Controller simply needs a 12v key on source to power the controller itself.
The fan motor has three wires going to it.
The 12V can be hot and ground wire can be grounded and the fan will never run. The PWM wire is a thin gauge signal wire that controls the fan on/off and speed through "Pulse-Width Modulation" aka PWM to the fan motors internal circuit board. This internal circuit board also has a built in "soft start" as well. Most brushless cooling fans have this feature. Newer vehicles handle PWM control through the ECM, many aftermarket ECMs also have PWM outputs. EBL does not so a external controller is needed.
the relay is just a failure point with a brushless fan. straight to main 12v with a fuse. I personally don't like battery terminal, I like getting that current load off the alt to battery wire. it's usually just 10/8g and long. it's much shorter to get to the alt from the fan motor usually. I like a jcase fuse because slow blow and easy to replace at any parts store. the factory c7 solid state 70amp fuse can be purchased and wired up. I don't like fusible links. they work but why when there's better options.
there's iffy info on this fan internal programming, but it's believed to have some current limitations programmed into it based on voltage. it's a 700watt fan that I could only get 36amp draw at max with the car running with 13.8v going to it. the theory is if you can get higher like closer to 15v which the ecm controled alts of the newer cars can do when needed. it will allow it to draw more amps and cool better. another reason to pick the higher voltage lug.
My reasoning for the relay on the fans power wire is so the EBL ECM is the master "on/off" for the fan. The EBL has some fan control parameters that I think will be nice to have in use. For instance, Engine Run to Start Delay.
The ebay link in the first post is the controller. Under the listings photos he has several photos showing pages from his manual for wiring it up in different scenarios. Pretty informative.
I saw they were low on stock and went ahead and ordered one JUST in case they went out of stock for an extended period. .
wow that little box does a lot. can't read all of it from my phone, but yeah that seems nice.
I don't know forsure if your older maf harness was like my map one. but it has a temp gauge for the dash on the head and a 3 wire for the ecm. so it definitely wouldn't interfere with the ecm if using the one wire one.
man, I'd almost be temped to use that ring terminal temp sensor and heat shrink it to the high side coming out of the condensor to run the fan smoothly based on head pressure and then let ebl run the fan at 50% or 100% based on coolent temp with its normal triggers. that is if you're going to use the ac all the time. like a Florida/south tx car where it's muggy, hot and miserable even at night haha.
clever little box. Definitely keep up the thread, I'd love to do this mod someday. seems like you could even pwm the stock. brushed fans with this too using a ssr or the pwm box from a c6 or the Ford one that's cheap.
I have a modified MAF harness. EBL is MAP/Speed Density based. But the CTS is a two wire if I am not mistaken. Even for your MAP car I believe? Then there is the temp gauge sensor that is one wire. I guess theoretically I could use that one as well, in my head I was planning on using the CTS going to the ECM.
I will definitely keep the thread updated as this progresses. Will be a month or so before I order the fan most likely. I'd rather do all my wiring at once so that means AC install at the same time. Along with a heated o2 sensor to start trying to run closed loop.
you know, you're right. it is a 2 wire coolent temp in the front of the intake. was thinking it needed to be 3 for some reason like a hall effect switch haha.
but yes, one wire in the head front and mine stock had a coolent switch in the passenger back side. something high like 240deg it would close and send a ground to over ride everything and turn both fans on. not that any of this matters, I think you're right. any will work for it, I'm guessing it's just taking a resistance measurement.
if anyone was concerned they could use the one wire for the dash or just add one in the rear passenger head just for the fan controller. plenty of options
Might have found another fan candidate 2021-2024 Chevy Malibu use a 600W (Same as C7) brushless fan that has a shroud measuring just shy of 18" x 27". Stock radiators are 17.25" x 26.25". So maybe with some creative trimming have perfect coverage. Fan Diameter is 15.25". Used prices under $150 and new GM Genuine $200. Should be same wiring scheme.
my Gen 1 volt has a nice set of brushless spal fans and shroud. they can be had cheap used too. I can probably measure them up. don't know the wattage.
*edit, you're right it was a 500w on the base and all the c7s are 600w now. I sware my memory haha, don't know where I got 700w from.
either one would probably be an upgrade for our cars thou.
GENUINE NEW Replacement Connectors, Terminals and Seals for Spal Kit 30130628 Brushless Fans https://a.co/d/2IGVH5w
I didn't really have the right crimper. gm used metric wire thickness and I forget if my 8g was a touch to big or 2 small. either way after crimping I wasn't 100% happy with it, so I flowed some solder into
them just to make sure.
my Gen 1 volt has a nice set of brushless spal fans and shroud. they can be had cheap used too. I can probably measure them up. don't know the wattage.
*edit, you're right it was a 500w on the base and all the c7s are 600w now. I sware my memory haha, don't know where I got 700w from.
either one would probably be an upgrade for our cars thou.
07-25-2024, 12:11 PM
