Thread: Electric Fan Wiring questions

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I have a vehicle with a Chevy 305 in it.
It has an electric fan on it but no fuse or thermo switch.
When buying a wiring kit for this fan what are the best temperatures that I should look for?
(The temperature that turns on the fan and the temperature that shuts off the fan)

Thank you.

I have an adjustable controller on my 350. It is set to come on about 205 and shut off at 190-195. I'm running a 180 thermostat. You want the fan cut-off temp high enough so that the fan will cut off under normal highway running.

If you have AC, you will need to run the fan any time the compressor is on or you will need a trinary switch to run the fan when the AC head pressure gets high.

A manual override switch could be handy, too.

You really have more than one choice here-we'll go from cheapest to the most expensive (and has the most options)-I am using quality components in these examples, and cheaper versions may be out there, but this is what I would consider-

As far as Fan control goes:
1. This unit will turn the Fan on at 200 degrees and turns it off at 185 degrees (it also has a Fuse built-in):
https://www.ronfrancis.com/prodinfo.asp?number=AR%2D30

2. This unit will turn on/off the fan at your pre-selected Temps
https://www.ronfrancis.com/images/AR-88NEW-Md.jpg

You will need a Fuse/Circuit breaker with this:
Something like this:
https://ceautoelectricsupply.com/pro...e-fuse-holder/

Or, this:
https://ceautoelectricsupply.com/pro...cuit-breakers/

I don't the start Amperage of your Fan(s), so I picked components capable of handling up to 100 Amps-usually, a high Amp Fan will use a 70
Amp Fuse-

3. This unit uses "pulse width modulation" (basically, what new cars today use, it "chops" the voltage up instead of turning it down), so, it varies in how long it runs as well as how fast it runs (it's the best of both worlds)-

https://www.summitracing.com/parts/prf-30141

You haven't told us which Fan you are running-is it a single speed or two speed Fan?

make sure you run a relay with the electric fan

you can save some time and make it adjustable without having to install another sending unit by using centechs unit, its available from speedway, Cooling Fan Control for Electric Gauges

I use the Digital Dakota fan control, it connects to your existing electric temperature sending unit and will run the fans after shut down for a specified time. A little more pricey, but it works great and is fully programable.
Electronic Fan Controller 70 Amp