Hey guys. I've searched and searched about this, and I've found a few threads that mention a fan switch, but none actually tell you how you can make one. I'm talking about a switch to make the cooling fans come on whenever you want, like the SLP fan control switch. Here's what I'm thinking, maybe some of you guys can tell me if this will work. The coolant temp. sensor, which I assume tells the fans when to come on, has 2 wires going to it, a red and a black. I'm also assuming that when the sensor reaches a certain temp, it completes the circuit to tell the fans to come on. So couldn't I tee a wire into both the red and the black wires, wire those to a toggle switch, and use the switch to complete the curcuit and make the fans come on? I'm talking about leaving the wires still connected to the coolant temp sensor, just tee into them, so it will still work normally if I don't need to turn the fans on manually. I've thought about this a while, and altho it seems painfully simple, is there any reason it wouldn't work? Thanks in advance for the input, maybe someone knows of a reason it wont work that I'm not thinking of.

 

Yes and NO. Depends on year and model, as different methods are used to control the fans.

 

Mine's a 97 Z28. But doesn't the coolant temp sensor tell something, whether it's the fan relay, the PCM, or whatever, to activate the fans? If that circuit is completed, what would make it NOT work?

 

Not sure of this but typically temp sensors work by changing the resistance according to the temperature they are exposed to. If this is the case then shorting the two lines and assuming the circuit is what you express here it may be, will likely drive the fans to an extreme presumably "max" .
I am with the other poster regarding the model year of the car involved. A diagram may help.

regards,
jim

 

Well i'll give ya a quick 101. the easiest way if you want. First off, there is a sensor in your rad that will tell your fans when to kick in. If your fans are not coming on, your sensor should be looked at.

Anyways, there are different types of switches, i'll just tell ya the quick 12v switch one.

Its a switch that just cuts off the circuit.. basically you need to get 12 v going into the switch.. then you need to take another wire, hook it to the out on the switch, and find the positive wire on your cooling fan.. hook that wire up to the fan, make sure the other wire on the fan is grounded, flick the switch, and your fans will turn on.. done and done.

 

its like midrange said, basically the easiest way to know it will work is to run a seperate power source and not have to try and use the one from the fans already that way you know you aren't disrupting there normal use. I just bought the slp switch, yeah it was a little bit of money but it looks clean works great and i don't have to worry that my fans won't kick on. took maybe 10 minutes to put in.