What e-fan has the lowest initial power spike?

[Fett]

I have the Taurus fan, hooked up with a 70amp relay and the VW thermo switch. Works great, only comes on for a few seconds when needbe. But the initial spike is huge. Granted my battery was unhooked while I did the rewire job two days ago, but the initial spike is much more than I expected. At a redlight, when typically the fan kicks on, the engine surges bad, almost to the point of stalling. It only happens for a second and the idle comes back to normal after a few seconds, but if there is a fan out there that might have a lower draw at initial start up....especially if it covers more of the radiator/condenser...I might try swapping them out.

Setup: 180 thermostat, VW thermo switch (198 on/189off), wired through a 70amp relay, with a 40amp fuse on the main power lead. I have a jumper wire going from the + side of the compressor coil, through a diode, into the relay to allow the fan to kick on as the compressor is powered up. I am thinking of switching that to the cycling switch...but I really don't use the AC much and haven't used it since the rewire. I did test it and everything works, just wanted to eliminate that as a problem.

 

[dastang2]

well if you have the stock alternator then that is your problem. not sure how much it gives out but people say to put a 3g 130 amp alt. when upgrading fans.

 

[Marlboro_Man]

Yep, Instead of spending more money on a different fan why not spend it on a 3G alt swap?

You won't regret having a 130 amp alt!

 

[Fett]

I have a 3g (130 amp) alt, I also have upgraded the wiring and ground (head to chassis).

 

[DMAN302]

Dcc Fk35 controller is what I use with my taurus..there is NO heavy spike and it controls temp perfectly.

 

[dastang2]

what kind of battery and how old is it, just wondering if it's time for a new one.

 

[Daggar]

Dcc Fk35 controller is what I use with my taurus..there is NO heavy spike and it controls temp perfectly.

Ditto

 

[Fett]

what kind of battery and how old is it, just wondering if it's time for a new one.

Motorcraft 750, it is about two months old. I am 99% sure I don't have a charging/battery issue. I guess I could have a ground issue, which I plan on adding a second chassis ground to the head.

I was thinking of changing fans anyway, because the Taurus doesn't cover enough of the radiator, in my opinion. There is too much blocking off with it, in order to get better radiator/condenser coverage. So I was hoping to find a fan that doesn't take such a huge spike. I haven't tested anything yet so I don't know for sure what the spike is, or what my alt is (I am going by stock volt gauge). So I will take a look at that tomorrow when I install my MSD.

 

[Marlboro_Man]

Well the dcc will definatly help. As i understand it starts the fan slowly so that there is no high amps drawn when it starts up.

Are you running underdrive pullies?

If you really want a new fan, check into an '06 GT fan. I LOVE mine!

Pic of my S-197 (06gt) fan
View attachment 449403

 

[Fett]

Have you tested it to see how many amps it draws?

 

[HISSIN50]

Any fan that pulls enough CFM for a modded V8 is going to have a large start-up draw - it's intrinsic to how the fan motor works with on/off switching.
Though not at all what you want to hear Chris, the Delta controller that Derek and Andy mentioned is about the only way to deal with it (Spal and FAL units might also have a soft start-up).

 

[Marlboro_Man]

Have you tested it to see how many amps it draws?

No , as i understand , you would need some fancy smancy (spelled EXPENSIVE) equipment to "load" the "wiring?" in order to see how many amps it draws.

I could be wrong though.

 

[macx]

An electronic controller is really the way to deal with a large fan - as pointed out a big fan is going to have a heavy draw spike on startup.

The DCC units are very popular with lots of Mustang owners. I ended up with a 3.8 V6 2 speed Taurus fan and a Flex A Lite soft start controller. Had it over a year, in OVER 104 degree temps in stop n go / stoplite driving with no problems with overheating or with the fan/controller setup. The FAL also delays fan start for 5 seconds when you start the car to avoid doubling up on draw if the engine is warm, and will run for a short time when you shut the engine down which can help avoid boil over if the engine is really warm. Also you can hook up manual over ride switches for constant on or total off. I've got a 100 amp alt on my 89 Linc Mark VII and, as the fan only runs a very small % of the time, haven't had the first problem with insufficient charging capacity. The FAL is just a tad cheaper than the DCC, but I'm sure either is a good choice. Just FYI, on Summit you'd need the larger of the 2 FAL units to run a Taurus or Mark VIII fan. Their info in their online catalogue is incorrect as to the amp capacity of the bigger unit, the one without the wiring kit.