relays neccesary on radiator fan's?
 

Just something I have been wondering if anyone has done, or thought about doing. Would it be possible to just bypass the relays on the radiator fans and just hook them up to a switch on the dash. I mean, you could just splice it into an acceleration or power source with a ground and turn them on after normal operating temp, right? Do the relays deal with the opening of the thermostat, if not, as long as the engine is at operating temp, if the fans were constantly on would it really make that big of a diff in the engine temperature?I live in Oklahoma and it is already getting into the 90's every day. Sometimes my fan's come on and sometimes they don't ( with no pattern, it is pretty random), so hence my question, are the relays absolutely neccesary and that critical to switch on the fans. I've just got done doing a single swap and that helped with engine temp inside the bay, and I've got an upgraded radiator and intercooler also. I know heat and improper tuning kills the rotary, so I am trying to keep it cool as possible. So my question basically is can I just hook them up to a switch and leave them on after the engine warms up. I was wanting to know the pro's and con's of this and if it would be worth doing. Thanks.

search "fan mod" and you can trigger your fans manually.

and yes the relays are necessary. Your switch would be pretty huge to handle the current the fans draw. This is where the relays come in handy, plus the relays allow for 3 speeds of operation.

Do not remove/bypass your relays...replace if not functioning properly.

well...yes there are actually 2 different "fan mods". One consists of tapping into the relays and making a ground (via switch) and the other actually connects to the ECU. The relay version is basically connecting the different relays to get the speed you want. Search to find this...

There is a unused female spade connector coming off of the Ecu (passenger foot area). Hook that baby to a switch and connect to ground and you will have automatic high fans. This version also lets the fans run on low for 10 mins after the car is shut down (great for cooling) if you want. Search for this version


I have both insralled to try both...Use both EVERYtime i drive and i have rock solid 180 temps with stock radiator. Thats soon to change though :-)

In other words, you will eventually weld the switch shut from the constant arcing that would occur from not using a relay due to the high current draw of the fan motors.

thanks. all good info.