Ok I had posted this question before but was getting confused with all the different ways to do it and I dont think the ways that were said will make it work like I want it to (correct me if I am wrong). I want to put a toggle switch in the interior of my car so that when I have the car turned off and keys out of it I can turn on the fan, but when I am driving around and have the switch off the fan will work as it normally does. Is it possible to do it this way?

Thanks again, sorry if I am annoying everyone with this

 

its possible but i would not recommend it because first you might drain the battery and second you will be running right off the battery and not through the relay..

i have a manual toggle switch and when the car is on i can ground that fan relay (100% safe) and turn the fan off / on...

 

another pic

 

I earthed the relay just as described in the tech article on this site, works great. I don't think running a fan with the engine off would acheive much in the way of cooling, it's just going to cool the water that exists in the rad.

just flip the manual switch on with the engine running for 2-3 minutes and you'll get the desired effect.

 

The problem is this. With the key off the contact side of the fan relay(s) going to its voltage source HAS voltage because it goes through a fuse link directly to the battery. However, the coil side of the relay does NOT have any voltage with the key off. That is the reason the fan(s) shut off when it's shut down and it's to keep the fan from running down the battery. What you want to do is mimmick one fan control circuit with an additional relay controlled by your switch. One end of the relay coil can go to a 12 volt source that is on all the time, the other end of the coil to one end of your switch and then to ground. Pick what fan you want to use(I would use the AUX-less time on it) and splice the contact wires from your relay directly across the two contact wires from the stock. Use the same guage wire for the contact side, the fan can draw some heavy current. This way completely retains the stock operation while giving you manual control with the key off. Personally there is no merit to running the fan without the pump circulating, but thats your call.

 

What gauge wire and what type of switch should be used in making a manual fan switch? How should the splicing be? Could I use those plastic connectors that you use pliers to push the staple into both wires?

 

You don't run POWER through the switch. You control the relay coil. Yes you can use a 3M quick connect and you should be OK with 16 guage wire as the coil only draws less than an amp. The relay socket has 2 heavy guage wires and two thinner ones. With the key on engine off pull the relay socket off and use a voltmeter and probe the connections. One heavy wire will have 12 volts, and one thin wire will have 12 volts both measured to the cars ground. The thin wire WITHOUT 12 volts is the one that gets grounded through a switch to turn on the fan manually. Put the 3M tap into that wire, run the end of the spliced wire to one term of the switch, and the other term of the switch run a wire from there to a good ground. Plug the relay back in and when you flip the sw it should work. I would cover the 3M tap with a little dieelectric grease to prevent corrosion.

 

Thank you Danno you explained it really well

 

I tore out the relay and and the wires and sensors to the fan. I ran a constant off the battery source and tied it through the toggle switch on the interior. Then I just tied it in to the radiator. Someone had three grounds for the darn thing and had a power cord made out of a house cord. I fixed the wiring once (by payting to have it done) then it got cook because the dumbass charged me 270 and did a **** job. Now it done right and wrked ever since. It is nice to turn it on while at a car show if the car is running hot so you can leave the car off while your doing something else. To tell you the truth though I am thinking about going with the flexlite dual electric fans because they look pretty bad ***. All a relay is, is a low voltage circuit controling a high voltage circuit. I ran a toggle switch for my fuel pump for the relay and then just ended up wiring it directly. The problem with both is a passanger might turn them off while your driving (had that happen before).