Fan override switch and heater control cable firewall hole questions

[Yama-Bro]

Hi Guys,

I'm working on my dash wiring. I added a hole for a fan over ride switch when I cut the dash. For some reason I thought that was part of the wiring system. Evidently not. SO, now that I have the switch in the dash, has anyone ever wired up one of the FFR switches to be a fan override, so it's just on all the time vs engine sensor controlled? I'd also like to use one of the indicator lights to show the switch is on. Has this been done before?

Concerning the heater control cable. Where is the best place to put the hole in the firewall for the cable to pass thru? It seems the best place for routing of the cable would be directly in front of the heater controls in the dash, but I just want to make sure there's nothing else that will cause me issues if I drill it there.

Thanks,

Frank

[steno]

An override switch is actually very common. I found an automotive covered switch that has an LED in the switch handle. The LED lights every time the fan turns on. I believe the build manual has a drawing on how to wire a switch.

[Blitzboy54]

I’m using a 3 pin “on on” switch (same switch as the high beams). My plan is rout the existing automatically controlled fan power through it and put a hot leg from one of the available 12v sources on the other. That way if the switch is on you’re getting continues 12v power to the fan but you shouldn’t need any new wires to the fan that that way. You could definitely jump the hot leg over to an indicator light which is a good idea.

[Rdone585]

I have an override switch for the fan. I mainly use it to cool off the radiator after coming off the track. The other times I use it is in summer sitting in traffic. The thermostat would have turned it on anyway, but sometimes in traffic I like to keep it running after the oil temp gets where it needs to be.

[egchewy79]

The dark green wire in the RF harness is the ground for the fan control. I wired an on-off switch in my dash to control the ground. You could wire a light in series with this to notify you when the switch is on. There are 2 dark green wires in the harness. I peeled the one out of my front harness to do to my dash switch. The other one is connected to my EFI fan control.

[Norm B]

The fan switch has been covered.
For the heater control cable, I would recommend you figure out the position of the switch on the dash first and then go as straight as you can out through the firewall behind that. The cable is very stiff and sharp bends greatly increase the resistance to motion.
Try to place the control valve with this in mind.

HTH

Norm