Assorted electrical issues

[atledreier]

ok, so, some further info on my issues.

I've noticed a clear correlation between the voltage drop and the cooling fans going full speed. Whenever the fans start i get lower voltage read in my dash, and it seems the alternator charge is affected. If I let the car idle the voltage drops all the way to battery voltage, (currently 12,2V with a loaded battery). Anything above idle and the voltage climb to around 13V. When the fans are behaving I get rock solid voltage just below the 14V mark.
My coolant temp reading in the dash is intermittent, but I see no correlation between the fans and voltage drop and the cluster gauge reading zero.
I've watched my ECU coolant temp via OBDII, and it seems solid and doesn't change when the fans go nuts. So, where does the ECU get the coolant temp from? I thought it was the same G62 sender that the cluster gauge used? What controls the cooling fans?

[atledreier]

Just for the record, changing the G62 sensor seems to have solved all the related issues with cooling fans, voltage drop and cluster gauge.