I have a 3g alt(130 amp), along with very strong grounds(4 AWG directly to ALT, with many more other grounds run on top of stock grounds), one 10 inch sub (300w RMS, nothing major). At idle, with the head lights on, it's at 14.1volts; not bad but but I'd like it to be a little higher, the green area is 14.4v +/-10%, at least thats what I've been told. That's not what this is about; thats just a background.

I just installed 2 Taurus e-Fans, and yea they move a LOT of air(~7500+cfm), blows the t-bird fan out of the water. I used the S55 relay, ran all 8 AWG wiring, etc., and had an 80 amp fuse on my 4 AWG ALT wire. The only thing I'm wondering may be a problem is that the positive wires running to the e-fans are actually the stock charging wires for my stock ALT. I figured that they're fuselinks, and used to support the entire truck's charging system, so they can run a few fans. Anyways, when I first ran it, the 80 amp fuse blew, so I bumped it up to a 100 amp, blew just as quickly. I ended up putting a 120 amp in; I figure since the ALT is capable of 130 amp (so is the wire), that size of fuse would still be okay.

When the fans turn on, my voltage drops below 13V, but very quickly rises back to 13.6V, then when they turn off the voltage returns to it's normal 14.1V. What I'm thinking of doing is the same concept as a home air conditioning condensor fan, more specifically a starter capacitor. When the fan first turns on, it draws a LOT of electricity, so to make up for it they have a starter capacitor. The capacitor is designed to basically be a rapid charge\rapid discharge battery, to help provide the fan the electricty it initially needs. There's something else that uses this same concept; car audio, with their capacitors. The idea behind those is that when the sub thumps really hard it needs a lot of electricity, so capacitors are put in as a "cushion." I have a 2.4 farad capacitor laying around that I was thinking of putting in my truck as a starter capacitor for my e-fans. Has this been done before? Am I missing something that would cause problems? I'll post any results I have, if I end up doing it.

 

Won't work. A cap will never have the energy storage capacity to provide the fan's inrush current needs.

What you need to do is either stagger the turn on for each fan, run them in series initially at startup (see diagram below for an example) or better yet - use a proper soft-start controller. The latter is my recommendation.



www.dccontrol.com has what you need.

BTW - the a/c start capacitor is a completely different animal - it's in seres with the start winding to induce greater phase-shift to enhance starting torque. This is an alternating current application - does not relate at all to a dc vehicle system.

MGD

 

or just run independent switches that you can power them on individually and lesson the tax on the electrical system

 

An AC capacitor isn't comparable to DC. The audio amp is much closer, but as MGD said: it won't work. A DC cap discharges in milliseconds, and it takes ~2 sec for the motors to get up to full speed. Holding the voltage high for another fraction of a second only produces more heat in a few of the motors' windings. To make a difference, you'd need a battery (and a capacitor ISN'T a battery), which brings us to the real issue...

Your battery or its connections are weak, and you're doing some really dangerous stuff with wires, fuses, & fusible links. You need to spend some quality time studying these:

. . . .

https://www.fleet.ford.com/truckbbas...7/c37_39_p.pdf

Never replace a fusible link with a fuse (or vice versa); never increase the fuse rating without increasing the wire gauge to match (or moreso); never assume a fusible link sized for one circuit will adequately protect or support a radically different circuit (or even a SLIGHTLY different one).

Until you get this straightened out, you should go back to a mechanical fan ASAP. You're liable to burn the truck to the ground with what you've done.

 

I hardly see how it would burn the truck to the ground when I have a fuse on every connection, but it is a concern none the less. My grounds are in good shape, I just went through them all again since I posted this, and they are all clean, non corroded, etc. On top of that, all of my connectors are soldered, with the exception of the distribution blocks I put in tonight. I never understood why ford used the starter relay as a distribution block, so I put one in tonight. I also have a distribution block for the Alt charge wire and e-Fan power wire, which I also changed to 4 AWG. After I did this, the idle voltage is at 14.4 volts, but when the fans turn on the voltage drops to 12.9V and holds. As far as the fuse rating for the ALT charge wire, I'm still well under what the wire can handle with my 120 amp fuse. I put the 80 AMP in there, and when I did it I knew that it was capable of more, and someday, it would most likely blow. I had it in there as kind of a warning sign, that something is using more amperage than it used to. I have not increased any fuse rating other than that wire, and that wire is fine, it's a high thread count, 4 AWG wire.

I never said that I was going to use an AC capacitor, I was only using it as an example for the concept. I was going to use a car audio capacitor, but as stated above, it won't work. I might still put it on, but only for it's original purpose, to help out with my stereo.

Thanks for clarifying on using the fuseable links, tomorrow I will switch them out with 8awg wires and a fuse block. If that doesn't fix it, it sounds like my battery is weak, I'll take it down and switch it out for a yellow top, I have a red top now. Yes it's from Autozone, but that wasn't my choice...when I got stranded my friend bought it for me and showed up with it. Ironically my Sears battery lasted for 6+ years...which is unheardof in Phoenix.

 

And there is a fuse on the factory, pre recall harness for the cruise control secondary safety switch...........

Are you really trying to run both fans at 100% at the same time ?
Any store bought kit will not try this, due to the basic lesson you learned.

 

"A" fuse isn't the issue. The WRONG fuse is the problem. Putting a 100A fuse on a wire that can only pass 50A and stay below 90°C means it will become a heating element during a heavy load or a short. If it gets hot enough, it'll melt thru its insualtion, and into that of every wire touching it, over its entire length. Once that happens, all bets are off. It's a cascade-effect failure.The concept of an AC capacitor & its use is entirely different from the concept of a DC capacitor & its use.

 

I agree, the weakest link will get hot, blow, melt (in the worst case), etc. which normally happens inside a fuse (yes I know it's not the EXACT same thing, but it's the general idea). If I had no continuous duty relay and just kept bumping up the fuse from my fan controller, that is exactly what would happen. I still do not see where I have done this. Yes I changed the fuse to a higher one on my ALT wire, but it is still WELL under what the ALT wire is capable of. If you are referring to the fuseable links on the fans right now, then I somewhat agree, and anything I'm not 100% confident in gets changed to something that I am confident in.

I don't know the background on that, but it must have been a faulty fuse or too large of fuse on a wire that wasn't designed for it. I guess I should clarify, when you have the correct fuses, with quality wires and connections, the fuse should blow. If not, thats why I have so many fuses on it. I have one on the wire going from the battery to the relay, one from the relay to the fan (ok right now it's a fuseable link but that will change today), one from the ALT to the Battery, and one from the battery to the trucks distrubtion block. That way, if one blows I have a relatively good idea of what is causing it.


Yes, I am running both on high right now, but I'm going to change it to low. I was following a DIY over at FSB, which said that the charging system would be able to handle both fans; with the exception of the guy having a 460, I have the exact same set-up. Actually, I'm going to put a switch in the cab and an additional relay under the hood so I can switch between low, high, and off (only to be used if I have to drive through a puddle etc.). I spent HOURS reading online about the Taurus fan, and schematics for fan controllers. Most of which (the diy ones) look to end up being just as much as the premade ones. This will be the best middle-ground for me, because even on low these things move 2700 cfm, so I'll still have over 5000 cfm of flow at idle. If that doesn't cool my 302, something else is going on. I have towed a trailer once since I had the truck (plan to do it more frequently in the future...moving to the country), so whenever I do it again, if I need to, I'll have that switch to give me some more flow.

 

No, it was an unexpected failure mode for the hydraulic switch that resulted in it getting hot enough to catch fire WITHOUT pulling more current than the circuit was designed to carry. So the switch caught fire, which set the brake MC reservoir on fire, which set the vehicle on fire, which set any nearby structure (like a house with people asleep) on fire.

.

Even with a VERY carefully engineered circuit, unexpected failures can happen. When you start throwing fuses & fusible links around like you're doing, it's almost inevitable.

 

Why not get a decent controller setup, rather than play switch and changing fan speeds.

Either get a controller that runs both fan at 60% at the turn on temp, and then steps up to 100% if the temp raises another 10* or get a controller that runs 1 fan at 100%, and if the temp raises the other fans turns on at 100%.

I did the Troyer fans and mounts with dual FAL VSC controllers on dad's RV. Dual controllers running the fans at 60% at turn on temp, and steps up to 100% if the temp increases another 10*. Solid state control of the fans, so no mechanical relay issues ( contact closure MTBF ).

This would cure the current inrush issue you appear to be seeing ( the blowing the fuses, and increasing the fuse size 40 A so it does not blow ).

Not too sure where you are getting the CFM rates, is this open air, or mounted ? If it is mounted, is it on the radiator in your truck ( towing package ) or in a car ?

If you are using fans that should be on a thinner radiator, and mounting them to a tow package radiator, that could cause an increase in current inrush. Also, if the fans are spinning backwards ( due to air moving through the rad ) and the fans need to overcome the anti directional spin, that can increase current inrush.

 

If that was happening, when the fans came on, they'd be blowing air forward out thru the grille instead of back toward the engine.

 

This is what happens when the fan is not powered. The free wheel state seems to be a slow reverse rotation direction, but enough to illuminate indicator lamps ( wind generator style ).

When the fan is powered, the anti rotation has to be over come, and then the spin up in the correct direction.

Common problem with e-Fans, and a long thread about the fuse holders melting on the Troyer kits.

 

For now, money, I've sunk enough into this project and as of now, I'm happy with the set up. I set up the relays for the low speed (2 40 A relays, one for each fan); and they still cool the engine with no problem. Best part is my voltage at idle (with headlights and blower motor on full) is at 14.1 V (drops to 13.8v when the fans first kick over). I have a toggle switch in the dash that either turns the fan to low, high, or off, as well as an indicator light that tells me when the fans should be on. The fans are still controlled by the temperature probe in the radiator, so they are not on all the time.


From various threads I have read on the swaps, taurus fans are very widely used for e-fan swaps. I've read about it on Jeep sites, Mustang sites, BMW sites, Chevy sites, Volvo sites, the list goes on. The majority of the sites quoted those numbers, I know that they most likely are aiming high, so my estimates are on the low side. At the end of the day, as long as it keeps my truck cool (and then some), I'm happy.

 

I don't see what I'm throwing around; you keep saying I am and I keep asking how I am, but to each their own, I guess. The fusible links have been removed, as I said I would do.