Electric Cooling Fans

[justin1987]

How does everyone with electric cooling fans on their radiators wire them up? Do you fix them where they come on anytime the ignition is on or with a sending unit where they kick on and off at a certain temperature? Thanks guys.

[aifilaw]

you will find most fans you buy come with a thermocouple probe and a relay to automatically turn them on at a specific temperature.
I by-passed this entirely and wired it up directly to a switch in the interior, the only time my car every had heating issues was at 120 degree's outside adn stuck in traffic, then I'd just flip the switch and it had no problems.

[NHCharger]

Mine is currently wired like aifilaw said. It's wired to a sensor on the return hose at the top of my radiator. I have a dial next to it so I can adjust at what temperature I want it to kick on. It's a pain in the ass. I've been meaning to wire it up like aifilaw's.

[red72chrgr]

NH, was this in conjunction with your regular fan?

[NHCharger]

NH, was this in conjunction with your regular fan?

Yes. I have a fan mounted in front of my radiator. Really helps when your stuck in traffic on a 90º day. The problem I have is on a hot day on a long upgrade with the car fully loaded (Coming back from Carlisle) the temperature will rise high enough to kick the fan on. At highway speed with the fan on, the fan seems to disrupt the flow of air to the radiator causing the temperature to to climb even higher.
I'm going to make sure I switch it over to a remote switch under the dash before Carlisle this year.

[Rolling_Thunder]

my EFI computer will handle the electric fans...    when I put them on that is   

[justin1987]

Thanks for everyone's input. I think we have decided to wire it so the fans kick on at 180 degrees and also wire an override switch in the console so we can turn the fans on anytime we want.

[aifilaw]

NH, was this in conjunction with your regular fan?

Yes. I have a fan mounted in front of my radiator. Really helps when your stuck in traffic on a 90º day. The problem I have is on a hot day on a long upgrade with the car fully loaded (Coming back from Carlisle) the temperature will rise high enough to kick the fan on. At highway speed with the fan on, the fan seems to disrupt the flow of air to the radiator causing the temperature to to climb even higher.
I'm going to make sure I switch it over to a remote switch under the dash before Carlisle this year.

This is the big problem, a PCM capable of EFI and turning on fans at cetain temperatures usually incoroporates a 30-40mph override control....which means the fan does NOT turn on when the vehicle is travelling at over a certain speed.
with absolutely no restriction (no grill, et cetera) 15-20 mph of vehicle speed is the same airflow being pushed through a standard radiator, so having the fan turned on does two things, it overdrives the electric motor and destroys it, and it can block true airflow from reaching the radiator and increase the heat.

For a standard electric fan, and relay unit with a thermocouple, this is not the case, so an override switch is a good idea. I also run the standard mechanical clutch fan and an electric up front...helped immensely.