Rewiring the thermo fans in the GQ (Lots of photos).

[ripper]

I've started on my wiring projects for our Trol, and thought I'd write them up in case anyone is interested in doing the same.

Did this job first because I thought it would be quick and easy.

I wanted to be able to turn the thermo fans on myself rather than waiting for the high pressure switch in the A/C receiver drier to switch them on.

Working out how to do it was made more interesting by the fact that my wiring diagram doesn't show any thermo fans at all.

After some searching I found the factory thermo fan relay is just behind the drivers side headlight. It's trigger is powered by a wire which comes from the A/C compressor wire, and it earths through the high pressure switch. So all I had to do was run a wire to a switch giving an alternate earth.

Here it is step by step.



A previous owner had tried to do what I wanted to do with the fans, but they had some problems :-)

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire1.jpg?t=1296479425


I guess you shouldn't use 25amp fuses in holders like this if you plan to short them out :-)
Amazingly this still works, but good luck getting the fuse out.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire2.jpg?t=1296479433


This is the connector on the pressure switch. I didn't want to cut into the original wiring, I just wanted to tee off it before the relay power went through the switch.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire3.jpg?t=1296479751


This is the terminal in the connector which I wanted to tap into. Lifting the tab with the point of my test light released the terminal so I could pull it out.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire4.jpg?t=1296479761


Here it's out.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire6.jpg?t=1296481855


Attaching the new wire was the worst part. I'm not great at soldering and it was really oily. Bad combination.
Sorry about the blurry photo. It's gives some idea of how much fun I had with it.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire7.jpg?t=1296480337


Finally soldered. Was wishing I'd just cut it and put a crimp in it by this stage. Especially as this was the second time I'd done it. First time round I did the wrong terminal :1087:

If you make the same mistake, you can probably just switch the terminals in the plug. I thought of that just after I cut the wire off ready to start again.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire10.jpg?t=1296480346


Here it is back in the plug.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire11.jpg?t=1296480756


And all plugged in again.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire12.jpg?t=1296480774

After this, all I had to do was to run the new wire to the switch the previous owner had put in the gear shift surround, and earth the switch.

The down side of this is that it only works when the A/C is on (which is still a lot better than it was), but I'm going to fix that when I put in a relay for my headlights. It means I'll have to cut the original wiring near the A/C compressor, but them's the breaks.


As a last photo. Here's how I make it easy to find my solder quickly. I don't use very much, and this bit wrapped around the cord of my soldering iron is usually enough to do a few jobs.

http://i152.photobucket.com/albums/s167/ripperdeals/GQ/resizedThermoFanRewire14.jpg?t=1296481306

[Bigrig]

Top post ripper!! Was discussing this very topic with my mechanic last week as the car heats up a fair bit before the fan cuts in (especially in stop start traffic in out heat!!).

[ripper]

For traffic and stop start stuff I think it's a must Bigrig.
I sometimes leave the engine running with the A/C when I get out to drop stuff off. Now it can get some extra air.
The last bloke put another relay in and completely rewired the fans. As you can see by the fuse holder, he didn't know what he was doing.
For someone who's good with a soldering iron, what I did would be really easy.

[AB]

Good post Ripper, I did this in my old ute with a 351 shortblock and it was a must in the traffic!

[NissanGQ4.2]

Great Post Ripper,

I have twin thermo's in my GQ and have a manual over-ride switch, but never thought about setting up an over-ride for the a/c fan as well, great idea :)

[nassin]

cool post thanks