how to: Electric Fan Conversion

[89LincolnTWNcar]

anybody have a set of instructions to switch to an electric fan? How do you wire up a thermostat to make it come on?

[Grand Marquis GT]

anybody have a set of instructions to switch to an electric fan? How do you wire up a thermostat to make it come on?

Theres a Hayden or Imperial switch you can buy at Advance where the electric fans are, and it hooks onto your rad somewhere, sensing the temp, and turning the fan on as needed

[DuceAnAHalf]

Theres a Hayden or Imperial switch you can buy at Advance where the electric fans are, and it hooks onto your rad somewhere, sensing the temp, and turning the fan on as needed

ive got one of those, and i dont think the thremostat works right. If it does it turns on way too high for me. i have the relay hooked to a switch. I turn it on when it is about 165 deg.

[gadget73]

I don't really like those "dry" sensors that jam into the radiator. Much better off with a wet sensor that plumbs into a heater line or something. You can get controllers from Summit or whatever, but I've also seen the whole kits with controller and fan for about what you'd pay for a controller.You'll also want a controller with an override for the AC so it kicks on when you turn the air on, or you can wire that into a relay easy enough. Soft-start is nice too but spendy. Relays are cheap. Also, (i use that a lot, don't i?) most big fans suck a lot of power so you might want to consider a bigger alternator. My Vic fan on high pegs out my 30 amp guage on the power supply, and pulls 22-25 amps on low speed. Low is all you need but its still a lot of power when you have a 65 amp alternator.

[89GrandMarquis]

how to: Electric Fan Conversion

Rather than thermostat switches, I prefer an actual controller. I've seen some from other vendors, but I prefer the one from www.dccontrol.com.

The benefits of this controller are numerous:
1) It has a "slow start" feature, so the charging system doesn't "see" the large current spike normally associated with starting a dc fan.
2) It is a "smart" controller, ramping up the fan speed to match the actual cooling needed. The fan speed will continually change according to the temperature sensor. Cold day or highway speeds, fan will run slow (or not at all).
3) The A/C interface is already built-in. I believe that this will start the fan at half-speed.

Yes, the price is high for the kit (about $110), but I believe it the best option, much better than just a simple on-off switch.

[DuceAnAHalf]

The fan im using runs through a 25-amp fuse, has not blown the fuse, so it must be using less than 25 amps, even on start-up.

[N A]

Everyone has to do the 130-amp alternator swap. :thumbsup: It solves so many problems and you don't have to worry when you do an electric fan swap or add a stereo and tv setup.

[89GrandMarquis]

The fan im using runs through a 25-amp fuse, has not blown the fuse, so it must be using less than 25 amps, even on start-up.

Just because it doesn't blow the fuse on startup doesn't mean it is drawing less than 25 amps. Most fuses will withstand more than there rating for a short while. Other fuses will withstand much more if they are time-delay types.

For example, a standard ATC 25 ampere fuse will pass 40 amps for 6 seconds.

Everyone has to do the 130-amp alternator swap.

I've got a 100-amp alternator (factory stock - has the electrically heated windshield defrost). Don't think I need the 130-amp version for my fan swap. Point is - not everybody should need one, but most do.

[N A]

It's an easy swap. (I'm not an alternator expert, but if the fan draws 25 amps from an 100 amp alt, it's down to 75 amps. If it draws 25 amps from an 130 amp alt, it still has 105 amps).

[89GrandMarquis]

It's an easy swap. (I'm not an alternator expert, but if the fan draws 25 amps from an 100 amp alt, it's down to 75 amps. If it draws 25 amps from an 130 amp alt, it still has 105 amps).

I'm not debating whether or not it is easy. I'm debating whether or not it is necessary. I don't have the cash to waste my money.

Not all of us NEED a 3G - that's all.

[gadget73]

One answer to that question: try it. If it holds solid voltage, then you're in good shape.