No Thermostat Fan Switch?

[Fricky]

Well, I have a Glanza S/Ep91 and I got it with the fan wired to turn on as soon as the ignition key is 'ON'. This was done by jumping a wire directly into the fan feed wire. Now, I have removed that wire and would like the fan to be temperature controlled but that is where I have run into problems. (1) My thermostat housing has no hole for a thermostat fan switch. (Somehow the orientation of the image is flipped 180 degrees. It is upside down and pointing to the left instead of right). There are no threads in the opening and the hole is basically sealed with metal.


(2) There is no wire on the engine looms that seems to have been for a thermostat switch if the housing was changed. I have verified this by following the wires on the the Fan No.1 relay in the engine bay fusebox and the wires from both sides of the relay switch lead into the cabin. One is on the loom that enters the passenger side while the other is on the loom that enters from the middle.


The empty relay slot is where Fan No. 1 relay sits.


The white/blue wire at the top right enters the cabin from the middle slot in the engine bay. The other wire is light blue/red (not visible here) and is on the bottom loom in this image which enters the cabin on the passenger side.

Now my question is, do you suppose that the radiator fan is controlled by an ECU? Or am I missing something here? Maybe the thermostat housing was switched with one that does not have a provision for a thermostat switch? Or am I following the wrong relay? Though I can confirm that when the bottom relay pin is grounded (in the second image), the fan turns on. That is how I am running it for now by grounding that pin so that it still runs all the time when the ignition is 'ON'. I would like to try and run it up to temp without grounding it and see if the fan kicks in.

Anyone with a better idea or explanation, suggestion? Thanks in advance!

 

[Fricky]

Well, I figured that this could not remain unsolved, so I went ahead sorted it out after a fashion. The absence of a tap to the thermostat fan switch (which is non-existent on my glanza) means that it was obviously not there in the first place and a wire that came directly from the fusebox was removed.

The solution
There is a light green/red wire that connects to the plug in the fusebox and it is connected to the fan relay. When you ground this wire with the ignition switch ON, the fan turns on. This wire goes into the car and is connected to the ECU. You can tap this wire to add your own thermostat fan switch. It is second from the right in this image (next to the white/red wire).



However, because I do not have the fan switch right now (or the provision for it unless I tap the thermostat cover), I opted to add my own by tapping into this wire near the ECU and connecting it to a switch which is connected to ground on the other side. So, I simply ground the light green/red wire by flicking a switch on the dash and the fan turns on as long as the ignition switch is ON.

On the other side of the plug where my finger is pointing is where the light green/red wire connects to the ECU. Please note that there are two similar coloured wires on that plug on that side. In its current orientation in the image, the wire on top is the correct one to use. To verify, simply ground it or check for continuity with the wire in the fusebox. That is how the switch looks on the dash next to the Hazards switch, it is not prettiest but it does its job.



So that's it.

 

[SKINY]

I would have just left it running all the time, what if you forget to flick the switch tho
Mine runs all the time for extra cool points

 

[Fricky]

I would have just left it running all the time, what if you forget to flick the switch tho
Mine runs all the time for extra cool points

There's that but you can simply leave the switch on. I do that sometimes and the fan runs continuously.