Great news that you've got an improvement BIG_MVS!
Without wanting to drag this on, I thought I'd let you know what I found on my 1990 GTA Turbo.
2 thicker wires (both white) going to the sensor at the top of the lug. Shorting these confirmed that this is the wiring to the fans. I didn't take the sensors out but this upper one had some lettering stamped on its edge, the last bit being 80/90 Z8T. I took this to confirm that this is the 80/90' sensor.
2 pinky/peach coloured wires that were a bit thinner go to the sensor at the bottom of the lug and the wires control the warning light. There is an extra shielding piece of the lug between the sensor face and the turbo heat-shield (which you can see on the parts catalogue diagram). I couldn't read any sensible lettering on this one.
So, it seems that this is set up just like Lee's A610. 110' at the bottom of the lug connected to the warning light, 90' at the top connected to the fans. As Lee says, seems there's a printing error in the parts catalogue.
The fans on mine seem to be working fine, so I'm guessing that is the correct - at least on later GTA Turbos
Jon
