Radiator Fan Toggle Switch

[DoctorPDR]

Also, remember to get a switch that can handle the high amps. The switch should be a DC switch rated at about 50 amps. Run heavy duty wiring as well. I use my toggle switch in traffic, which helps to keep my Spider cool.

I don't think all that is necessary if you are only connecting the two black wires from the switch to the rocker switch. My rocker switch is rated for 25 amps and works just fine. Wire should be 12-14 Gauge, which is the size of the wire on the switch, I do believe.

[danaspider]

DoctorPDR, while putting the switch across the temp switch achieves what you want to do, adding a relay would be a better idea. Then the relay is carrying the current and you don't have to worry about a switch burning up when it can't handle the currrent flow. Also, with the proper wiring of the relay it will drop out when you turn the ignition off and you don't have to worry about running the battery, yet it will still allow the fan to run via the temp switch to after shutdown cool down cycle.

Also your light may not work on the switch, since you are just switching a ground, no 12 v present. With the relay can get 12v and gnd to the switch to light the light.

[DoctorPDR]

With help from Mark, I was finally able to wire this damn radiator fan properly in order to turn it on manually. The manual operation will now operate in parallel with the automatic mode of the radiator fan switch. The reason I did this mod was to have the ability to turn the fan on if I were in rush hour traffic, a car cruise, etc. That way I can just turn the fan on and leave it on. After the wiring is complete, should you turn your fan on manually and turn off the ignition key, the fan will also turn off. However, if it is running in automatic mode with the ignition on and then you turn your ignition off, it will stay on and complete its cycle. I will post the information on how the wiring should be done in simple layman terms (no schematics, just simple steps and instructions), since electrical is not really my strong point.

List of Parts:

1. Standard Relay with 4 or 5 terminals. The terminals should be numbered 30, 85, 86, & 87.
2. SPST Rocker Switch (25 Amp) with LED illumination and three terminals. My terminals were labled "Load", "Power", and "Ground."
3. Optional In-line fuse.
4. You will also need some heavy duty 12 gauge and 16-18 gauge wire, wire connectors, wire terminal plugs, and some heat shrink.

Instructions:

Step 1: Disconnect your car battery.
Step 2: Take the black wire coming from the radiator fan and splice another wire into it. You will take this lead and plug it into terminal # 87 of the relay you just bought.
Step 3: Cut an appropriate length of 12 gauge wire and plug that into terminal # 30 of the relay. You will mount the other end of this wire to the frame of the vehicle. You can also plug the other end into an available terminal on the "pod" of the inner fender where all the other ground wires are plugged into. Make sure to use 12 gauge wire in this step, since this wire will generate some heat.
Step 4: Now cut another ground wire (16-18 gauge) of apropriate length and plug one side into terminal # 86 of the relay, and the other end to the "pod" of the inner fender. If you don't have any more terminals available on the "pod", then drill a hole close by where the relay will be located to ground the wire.
Step 5: Cut another length of 16-18 gauge wire of appropriate length and run this wire through your firewall. This wire will plug into the "load source" of the rocker switch and the other end will be plugged into terminal # 85 of the relay.

After you have completed all these steps, you will now start working inside your car. You have two terminals left to wire on the rocker switch.

Step 6: Cut an appropriate length of wire for your ground. You will connect one end to the "Ground" terminal of your rocker switch and the other end to a suitable ground location under your dash.

Step 7: Cut an appropriate length of wire for your power. You can add the optional In-line fuse to this wire, but just make sure you make it accessible when it's tucked back up into your dash. You will connect one end to the "Power" terminal of your rocker switch and the other end you splice into a wire that has constant power that is always on when you turn your ignition on. This can be a wire in your ignition or even the cigarette lighter.

Step 8: Tidy up all of your work, re-connect your battery, and fire up your car. Now turn on the fan manually. It should turn on with the LED of the rocker switch illuminated. With the fan on, turn your car off. The fan should also power off along with the LED of the rocker switch.

Now start your car back up, turn the fan off, and let it warm up to operating temperature. Do not turn the fan on manually. It should automatically turn on by the radiator switch (located at the bottom of your radiator) once it's up to temp.

MOD DONE!

I will post pictures soon of where I mounted my rocker switches. I have a total of three, where one is for the radiator fan, one is for a set of Hella Fog Lights I just recently purchased from Mark (along with a custom mounting bar), and the other may be used for something in the future. I don't have any need for my third rocker switch at the moment, but I wanted everything to look streamline on my dash. Obviously, you will need to find a suitable location for your rocker switch before or after you complete this wiring mod.

Thanks again for all your help MARK!

[Tango]

Is there an easy way to hook up an indicator light instead of a switch that will tell me when the fan is on (or at least when the switch is closed)? Something that doesn't use much power, maybe a diode? Is it as easy as running a wire from the output side of the rad temp switch to a dash mounted light, then to ground? Do you need any kind of resistor to prevent draining off power that you want to go to the fan? Yes, my electricity physics are rusty.

I'm new to where to go for parts for this type of thing (in Canada).

T

[danaspider]

Tango, you could run a wire from the temp switch, (the switched side) or light on all time. But the light would not go to ground, it needs to go to 12v, as the temp switch is going to ground.

[Tango]

i better get my circuit diagram out.

[brunorahl]

Get a generic 30amp, 5 prong relay. Add a Y splice to the ground wire coming off the motor. Run that wire to relay post 30. Run a wire from relay post 87 / 87a to ground. Find a wire that's hot when the key is on, ONLY. Run that to a toggle switch and then on to relay post 86. Run a wire from relay post 85 to ground.

The fan will still work as Fiat made it, plus you can turn it on when you want. The relay and switch will only be active when the car is on, so you won't kill the battery.

[DoctorPDR]

Get a generic 30amp, 5 prong relay. Add a Y splice to the ground wire coming off the motor. Run that wire to relay post 30. Run a wire from relay post 87 / 87a to ground. Find a wire that's hot when the key is on, ONLY. Run that to a toggle switch and then on to relay post 86. Run a wire from relay post 85 to ground.

The fan will still work as Fiat made it, plus you can turn it on when you want. The relay and switch will only be active when the car is on, so you won't kill the battery.

Refer to five posts up...