DB7 cooling: fans/idle speed/logic information

[Britjim]

I own a 2000 DB7 Vantage with an overheating problem. So far, the thermostat and coolant have been replaced. This helped but hasn't completely solved the issue. When the engine temp. is above normal the idle speed increases. Is this normal? I checked the fans by applying power to directly to the fan wiring and they both work. I then looked at the fuses (30A) and one was blown. I suspect this has happened with the previous owner since I found several 30A fuses in the glove box, some new and some blown. I am in the process of checking this out and need information. I want to understand the electrical logic employed. How are the fans switched on? A simple temperature switch or some ECU logic based on a temp. sensor input? What is the most likely cause of the high current that pops a fuse? I suspect the problem resulting in the blown fuse is the reason for overheating since the engine cools off quickly when the car is moving.

[N7GTX]

You may be able to get the wiring diagram and a lot of help on the Aston Martin DB7 Appreciation Society pages on Facebook. I only have the i6 diagrams so cannot help you.
The fuse blowing is either a short or the fan motor is taking too much current. If you haven't already, clean the terminals at the relays and the motors to eliminate them.